© Copyright
JASSS
Rosaria Conte and Mario
Paolucci (2001)
Intelligent Social Learning
Journal of Artificial Societies and Social
Simulation vol. 4, no. 1,
<http://www.soc.surrey.ac.uk/JASSS/4/1/3.html>
To cite articles published in the Journal of Artificial
Societies and Social Simulation, please reference the above information and
include paragraph numbers if necessary
Received: 01-Sep-00
Accepted: 24-Nov-00
Published: 31-Jan-01
Abstract
- One of the cognitive processes responsible for social propagation is
social learning, broadly meant as the process by means of which agents'
acquisition of new information is caused or favoured by their being exposed to
one another in a common environment. Social learning results from one or other
of a number of social phenomena, the most important of which are social
facilitation and imitation. In this paper, a general notion of social learning
will be defined and the main processes that are responsible for it, namely
social facilitation and imitation, will be analysed in terms of the social
mental processes they require. A brief analysis of classical definitions of
social learning is carried on, showing that a systematic and consistent
treatment of this notion is still missing. A general notion of social learning
is then introduced and the two main processes that may lead to it, social
facilitation and imitation, will be defined as different steps on a continuum
of cognitive complexity. Finally, the utility of the present approach is
discussed. The analysis presented in this paper draws upon a cognitive model
of social action (cf. Conte & Castelfranchi 1995; Conte 1999). The agent
model that will be referred to throughout the paper is a cognitive model,
endowed with mental properties for pursuing goals and intentions, and for
knowledge-based action. To be noted, a cognitive agent is not to be
necessarily meant as a natural system, although many examples examined in the
paper are drawn from the real social life of humans. Cognitive agents may also
be artificial systems endowed with the capacity for reasoning, planning, and
decision-making about both world and mental states. Finally, some advantages
of intelligent social learning in agent systems applications are discussed.
- Keywords:
- Social Learning, Social Facilitation, Cognitive Modeling
Introduction
- 1.1
- Two main theses are presented in this paper regarding the phenomenon of
imitation:
- Imitation needs to be modelled in cognitive terms. Far from being a
merely behavioural notion, the phenomenon of imitation can be defined in a
specific and useful way only if its mental correlates are detected.
- Imitation is a special case of social learning, which in turn plays a
role in behavioural and cultural transmission. In this paper, the social
propagation of behaviours and culture is seen as a complex phenomenon that
may be realised by means of either social cognitive or non-cognitive
processes (see Figure.1).
|
Figure 1. Social Propagation
|
- 1.2
- By a cognitive process, we mean a process (a sequence of
operations, such as reasoning, decision-making, etc.) upon symbolic
representations (e.g., goals and beliefs). A social cognitive process is
accomplished upon social mental representations (e.g., social reasoning means
reasoning upon social beliefs). Finally, a social mental representation
mentions another agent and possibly one or more of her mental states (for
a discussion of these notions, see Conte &
Castelfranchi 1995, and Conte 1999).
- 1.3
- There is a fundamental difference between the approach to social cognition
adopted in this paper and other more classic conceptions of social cognition
(e.g., Bandura, 1986
or Berkowitz,
1984). In these well-known versions, a social cognitive model puts
together internal (cognitive) and external (social) factors of action. In the
version presented here, a social cognitive model brings about a subset of
cognitive factors, i.e. social representations (representation about others
agents and their minds) and the operations accomplished upon them.
- 1.4
- One[1] of the
cognitive processes responsible for social propagation is social
learning, broadly meant as the process by means of which agents'
acquisition of new information is caused or favoured by their being exposed to
one another in a common environment.
- 1.5
- Social learning results from one or another of a number of social
phenomena, the most important of which are social facilitation and imitation
(see Figure. 2[2]).
|
Figure 2. Social learning |
- 1.6
- In this paper, a general notion of social learning will be defined and the
main processes that are responsible for it, namely social facilitation and
imitation, will be analysed in terms of the social mental processes they
require.
- 1.7
- The rest of the paper will be organised as follows. In the next section,
where some classical definitions of social learning are analysed, a systematic
and consistent treatment of these notions is shown to be missing. In the
following sections, a general notion of social learning is introduced and the
two main processes that may lead to it, social facilitation and imitation,
will be defined as different steps on a continuum of cognitive complexity. In
the final section, the utility of the present approach will be discussed.
- 1.8
- The analysis presented in this paper draws upon a cognitive model of
social action (cf. Conte &
Castelfranchi 1995; for a synthesis, see Conte 1999). The
agent model that will be referred to throughout the paper is a cognitive
model, endowed with mental properties for pursuing goals and intentions, and
for knowledge-based action. Therefore, some notions drawn from the formal
study of mental states will also be employed.
- 1.9
- To be noted, a cognitive agent is not to be necessarily meant as a
natural system, although many examples examined in the paper are drawn
from the real social life of humans. Cognitive agents may also be artificial
systems endowed with knowledge and the capacity for reasoning, planning, and
decision-making. The interesting question concerning artificial systems is
what are the mechanisms that must be implemented at the agent level to enable
them to learn from one another. Are the mechanisms allowing agents to learn
from their physical environment sufficient for them to learn also from or
perhaps through their social environment? If not, which additional properties
are needed? And, earlier than this, what does social learning mean, which
social phenomena are referred to by this notion?
Classical definitions
- 2.1
- It has been observed (Laland &
Odling-Smee, 1999) that the term social learning describes a "ragbag" of
heterogeneous phenomena, with a variety of functions. A systematic treatment
of these notions is still wanted.
- 2.2
- In Bandura (1977), social
learning is based upon either extrinsic or intrinsic[3] factors or
motivations. Intrinsic social learning occurs in social facilitation. It
occurs when people are led by others to acquire new means (intrinsic) for
achieving old goals. Extrinsic social learning occurs in imitation, when
people learn through the observation of attractive and consistent social
models. By observing their social models and recording when these apply
reinforcing mechanisms (extrinsic), people learn to reinforce themselves
(self-reinforcement) to do what others have reinforced, and abstain from doing
what others have punished.
- 2.3
- In this apparently simple and elegant theory, imitation is still based on
the mechanism of reinforcement. What about imitating social models who
are unaware about their role and therefore unable to apply prize or penalty?
- 2.4
- Furthermore, imitation is not an easy phenomenon to define. Quite often,
it is perceived as a merely behavioural phenomenon. In the typical
behaviourist view, recently reworded by (Blackmore
1999), imitation is defined as copying a new form of behaviour. But
what is a new form of behaviour? As a long line of psychological thought has
shown (see Plotkin 1994,
for a clear summary), behaviour is essentially a goal-directed or end-directed
activity. In this sense, coughing is not behaviour, unless one coughs to
signal disappointment or disapproval. When one learns to raise one's arm when
meeting another (known) agent, one learns a new behaviour, although the
movements involved were already part of one's action repertoire. In this
sense, learning a new form of behaviour by imitation means learning a
use or meaning (read, goals) which may "in-form" (Plotkin 1994)
a given activity. It then becomes apparent that imitation leads to agents
acquiring novel behavioural in-formation from others, and therefore implies
their capacity to draw such information from observed behaviours. Some
ethologists (see Mitchell
1987, cited by Visalberghi
& Fragaszy 1999) propose five clauses for a definition of animal
imitation:
- something C (the copy of the behaviour) is produced by an organism;
- where C is similar to something else M (the Model behaviour);
- observation of M is necessary for the production of C (above baseline
levels of C occurring spontaneously);
- C is designed to be similar to M;
- the behaviour C must be a novel behaviour, not already organised in that
precise way in the organism's repertoire.
- 2.5
- According to this model, imitation occurs when a given behaviour is
designed to be similar or modelled upon that shown by a given target.
In other words, a given agent is assumed as a model for several and sometimes
convergent reasons (observing the consequences of that behaviour on the
target's survival, assuming the target as a social model, obtaining approval
from the target, etc.). How to account for such an intuition in an explicit
and systematic way? What does it imply in mental terms, which cognitive
properties, representations, etc., are required by this notion of imitation?
- 2.6
- To sum up, what is needed is:
- A clearly defined core notion of social learning, which accounts not
only for (i) emulation-based processes, but also for (ii) other processes
(e.g., purely instrumental social learning); and (iii) is not based only on
the reinforcement laws.
- A number of specific models corresponding to imitation, social
facilitation, etc.; as will be shown, in order to distinguish among these
phenomena, the mental states and processes involved must be modelled.
- An account of the intuition that, at least in imitation, the behaviour
is intended, or at least designed, to be similar to the model's.
- 2.7
- In this paper, an attempt to meet these requirements is made. Rather than
a comprehensive theory, what is offered below is a preliminary model of a
complex phenomenon, leading from observation of others and their behaviours to
acquisition/transmission of these behaviours and the associated beliefs.
Behaviour and Mental Representations
- 3.1
- One of the most important aspects of social life and intelligence is the
diffusion of mental representations (e.g., beliefs) among agents. Here, it
will be said that there is transmission of mental representations through
behaviours, when a given behaviour is "interpreted" as based upon some (even
very simple) beliefs, goals, etc., which may or may not coincide with those of
the observed agent. We will say that mental states leading to the same
behaviour are equifunctional. A crucial aspect of this view of
behavioural transmission lies in the role played by equifunctional mental
states. One could argue that mental states are irrelevant in a model of
behavioural transmission, since what is important is their role, not their
content. Indeed, one can assume that if the same behaviour spreads over a
given population, the underlying mental states must have been at least
equifunctional, if not identical, and that is all one needs to say about them.
Below, this view is challenged thanks to a fundamental analytical argument: a
theory of mental processes is necessary to understand/predict social phenomena
that involve mentally complex systems, such as humans. Let us see why in some
detail.
- 3.2
-
- A theory of cultural transmission should account not only for the
outcomes of the process, but also for the process itself, and
a model of the process of cultural transmission implies a model of the
mental states involved in it. Democratic institutions (objective
outcome) tend to spread at the world-wide level. The problem is how and why
this happens, whether under the effect of economic needs (free-market) or
thanks (also) to widening expectations and claims (mental
process) for the acknowledgement of human rights.
- Mental processes that are equifunctional with regard to short-term
effects of behavioural transmission may have different long- or mid-term
effects. Internet access spreads thanks to different mental processes, for
example, because it is expected to reduce the costs of exchange, or because
it is expected to favour cooperation. Both types of mental processes could
have promoted Internet diffusion, but only the latter interpretation will
ultimately favour the spread of a "participatory" or communitarian use of
Internet (for example, civic networks).
- In order to predict or account for the stability of specific cultural or
behavioural items, one needs to investigate what are the underlying reasons
or interpretations. Suppose that, in the daylight, a car proceeding on the
opposite side of the street flashes while approaching you. If you interpret
this as a greeting, the chances that you will reproduce the same behaviour
while approaching other cars are probably not very high. However, if you
find that an automatic speed limit controller is situated some meters ahead,
the chances that you will re-interpret the previous driver's behaviour as a
convention (e.g., drivers informing one another about speed limit control)
increase. Consequently, the chances that you adopt the same behaviour with
other drivers increase accordingly.
- A model of the mental processes involved in cultural transmission is
fundamental to enable artificial systems to learn from (natural or
artificial) others (this is particularly important in info-societies, which
are structurally hybrid multi-agent systems). Which properties should agent
systems have in a context like e-commerce in order to be able to accept
useful social laws or conventions (e.g., respect privacy or decency)? Which
mechanisms will enable agents to avoid or resist useless or undesirable
social influence (for example, don't cheat if this results in a loss of your
client's reputation) to control and select external sources of information?
These are new challenges for the development of information societies. Of
course, one can implement rules and conventions as simple machinery, i.e.,
as action constraints. But in such a case, how to safeguard the autonomy and
flexibility of artificial systems, if autonomy is, as is usually claimed by
agent systems scientists, a useful property for an artificial system to
have? How to enable them to violate social norms and conventions in all the
circumstances in which violation is warranted (for example, in order to
comply with more important but incompatible norms)?
Social Propagation of Behaviours
- 4.1
- Social transmission of behaviours may not imply the transmission of
representations (see the examples in List A of the Appendix to this paper).
Think of the spread of the behavioural expression of emotions, which abound in
everyday life (Freedman &
Perlick 1979). This actually falls in the wide and generic category of
behavioural contagion, which has been explained in terms of two different
mechanisms (see Marsden 1998):
social learning, as described in section 2, and "social
release" (Ritter
& Holmes 1969; Wheeler 1966;
Levy & Nail
1993; for a recent analysis, see again Marsden 1998).
Social release essentially consists of a mechanism by means of which, in
presence of others, individuals release behaviours which belong to their
repertoire but which were inhibited.
- 4.2
- Both groups of theories, indeed, fail to capture the main difference
between contagion and other processes of propagation. Social learning theories
do not account for any such difference; the social release theories reduce
this difference to a strictly behavioural difference: a behaviour which
spreads through contagion is already in one's repertoire, whilst a learned
behaviour does not yet belong to one's repertoire. This view has been already
criticised in section 2[4]. Moreover,
the social contagion is sometimes meant in the rather broad sense of social
propagation (Reber 1995; Marshall
1994). For example, it is unclear what is meant by "suicidal contagion"
(cf., for example, Phillips
1974). The spread of suicide is a rather complex phenomenon that may be
due to several mechanisms including but not reduced to contagion. The theory
of priming effect (Berkowitz
1973, Berkowitz
1984, Berkowitz
1986) applies a social cognitive explanation to contagion phenomena. The
priming consists of a temporary exhibition (statistically significant but not
self-conscious) of behaviour as caused by "thoughts" activated by the observed
one. Such a temporary "release" of behaviour under social influence should not
be classified as learning, but rather as social release. This theory is partly
behavioural and partly cognitive, indeed. The latter segment of the process
hypothesised by Berkovitz, from an activated thought to a behaviour release,
is cognitive. But the former segment is not: there is no "transmission" of
representation from one agent to another, but a re-activation of the same
representations under the effects of a given perception (something similar to
the Party shower effect in List A at the end of this paper).
- 4.3
- Behaviour can spread also through social cognitive processes (see List B
in the Appendix), mediated by the agents' social goals and beliefs, and by
their social competence (e.g., their social reasoning capacity). The essential
difference between the Lists A and B lies in the role played by the agents'
mental processes in the spread of a given behaviour. Unlike List A, List B
contains several interesting examples of social learning. What is needed is a
notion of social learning which accounts for the examples in List B, but rules
out those appearing in List A.
Social Learning
- 5.1
- In this section, a subset of phenomena of propagation is addressed, in
which mental representation(s) (explicit beliefs or rules, procedures, etc.)
propagate from one agent to another, and only as a possible consequence, the
behaviours that are based upon them are reproduced. This takes place among
socially situated agents, which share a common environment and are therefore
likely to observe one another.
- 5.2
- As announced in the introduction, social learning is seen here as a
process of learning caused or favoured by the agents being situated in a
common environment and observing one another. In this sense, the other is not
only perceived as a criterion for comparison and self-evaluation, but also as
a more neutral source of information, which may help or speed several forms of
instrumental learning. In addition, social learning is here seen as a
multilevel phenomenon, and is defined in a gradualist way starting from an
elementary notion. In a minimal sense,
social learning is the phenomenon by means of which a given
agent (the learning agent) updates its own knowledge base (adding to, or
removing from it a given information, or modifying an existing
representation) by perceiving the positive or negative effects of any given
event undergone or actively produced by another agent on a state of the
world which the learning agent has as a goal.
In the following
section, the examples discussed will help clarify this definition.
Social Facilitation
- 5.3
- Here, a general[5] perspective
on social facilitation is taken, allowing to include the notion of local or
stimulus enhancement as suggested by the animal ethological literature (for a
review, see Heyes
& Galef 1996). For ethologists, local or "... stimulus enhancement
refers to a process in which one animal directs another animal's attention to
a location (or object) in the environment" (Laland &
Odling-Smee 1999: 5).
- 5.4
- More generally, in some species (included humans), one's acquisition of a
given piece of information about the environment may be caused by another
agent although this does not necessarily imply the propagation of such an
information from the mind of the latter agent to the mind of the former.
Consider the case in which a given agent, finding shelter from the rain under
a tree, is struck by lightning. An accidental observer will learn something
new from her fellow, that is, "never stop under a tree when it rains". In such
a case, one agent learns from another without the latter's behaviour to
propagate. The example shows that social facilitation is very close to an even
more elementary type of learning: the observer might infer the same lethal
effect even by watching the tree being struck by lightning. However, as shown
by the ethological literature, learning is enhanced by observing the effects
of actions or external events on conspecifics. What happens to a
conspecific will (be expected to) concern me more than what happens to a tree.
This point deserves further clarification. Not only the outcome of the process
(struck by lightning) is bound to elicit the learning process (don't stop
under a tree when it rains), but also the process (the entity observed)
leads to interpret the outcome as relevant for oneself.
|
Figure 3. Social learning with and without behavioural
propagation |
- 5.5
- Social facilitation is a very elementary type of social learning, in which
the beneficiary does not necessarily attribute the other any goals or other
mental states. In the above example, the same effect might have been probably
achieved by the observer, had it seen a piece of wood, rather than a fellow
agent, struck by lightning. Of course, if the input comes from an agent, the
stimulus to the observer's inference and the chance that she gets new
information out of it are higher. This is because the probability that the
event observed has effects on the observer's goals (which may overlap with the
input agent's to some extent) is higher.
- 5.6
- There are different types of social facilitation phenomena, according to
the role played by the input agent (which will be called "S", the Source) in
the Observer's ("O") learning process and in its representations. In social
facilitation, S may operate as a
- pointer or "bookmarker": S acts in such a way as to increase the
chances that O perceives a given event, which triggers O's learning process.
This is essentially what ethologists call local enhancement. As an
example, while running after S, O discovers a new region that she[6] had never
realised before. Here, there is no need for S to transmit his own beliefs to
O (S might simply escape from O in an unknown direction). O, in her turn,
does not acquire a new piece of knowledge by reconstructing S's mental
states, nor by observing the effects of a given event on S's fate. S is a
mere accidental cause of O's discovery. S acts as a sort of bookmarker or
pointer. Here, O learns a new section of the world map.
- Qualifier: S's features may characterise a given environment, and
help O characterise or identify it. Suppose I am in a foreign country and
badly need a restroom, but cannot tell from the written signs which is the
ladies' and which is the gentlemen's toilet. One possible solution is wait
and see which way will take the next newcomer of either gender.
Interestingly, the social cognitive process that occurs is the same but
leads to alternative behaviours: if the newcomer belongs to my gender I will
act alike; if he is of the opposite gender, I will take the alternative way.
- Activator. This is shown by the example of milk bottle top
opening in British tits (Hinde & Fisher
1951). Let us see how Laland and Odling-Smee (1999: 6)
discuss this example: "These birds learned to peck open the foil cap on milk
bottles... . Hinde and Fisher found that this behaviour probably spreads by
local enhancement, where the tits' attention is drawn to the milk bottles by
a conspecific, and after this initial tip off, they subsequently learn on
their own how to open the tops". However, Hinde and Fisher's explanation is
insufficient. The learning process is facilitated by S in a double way: S
draws O's attention on a given object, which possibly "activates" O's goal
of manipulating it, and therefore leads O to exhibit the same behaviour as
S. Here, propagation occurs. However, there is no need that O actually
represents S as a "manipulator", nor, a fortiori, that O attributes S any
capacity or mental states. S points to a new object that might activate a
built-in routine for manipulation. An analogous example is offered by the
acquisition of dietary preferences among rats (Galef 1996;
see again, the discussion of this example in Laland &
Odling-Smee's 1999: 6), which prefer "to eat foods that other rats have
eaten".
- Belief-holder: a subset of S's inferable beliefs may help O to
identify and understand the environment. An interesting example of this
phenomenon is offered by people's recognising a given (social) setting by
observing others' behaviour: if someone is standing on the edge of the
sidewalk, it is probably there where the bus stops. In such cases, O resorts
to her pre-established beliefs about S (pedestrian): people standing up
motionless in the street usually are waiting for someone or something.
Interestingly, O may have a pre-existing goal (taking the bus), which S
helps her to achieve by marking how to verify its preconditions (find the
place where the bus stops). Alternatively, this goal may be activated by O's
perception of S's behaviour and by inferring the associated mental states (O
is walking to destination, but since she understands that a bus-stop is
near, she may get on the next bus). In such a case, social facilitation
allows for social propagation: a given (set of) belief(s) travels from S to
O. Indeed, O decodes S's beliefs from his behaviour and incorporates them
into her knowledge base (unless she finds evidence that S is wrong or her
inference is incorrect).
- Experimental "testbed": this is shown by the example of looking
for a shelter from rain. By observing what happens to S, O learns to avoid
trees. Here, O learns a negative effect of a known plan of action. Examples
of this sort abound in social life: agents not only observe and learn given
behaviours from one another, but also avoid the costs of a direct
experiment, and learn the positive or negative (side-)effects of current
plans/procedures etc.
- Subject of norms, standards, conventions: S's behaviour may
indicate existing standards, norms, and conventions. Independent of whether
O will decide to accept or reject them, and of whether to comply with them
or not, others may be a fundamental source of information about formal or
informal norms, customs, habits and any other factor of regulation of one's
(social) conduct. More basically, think of O as an external observer, an
anthropologist or ethnographer. She may learn a lot about how a given
society is organised, differentiated, what are its social hierarchies, etc.
from the behaviours of the society's members. But even independent of
standards and norms, O may learn a lot about social categories, reputation,
roles, etc. by observing how agents interact with and react to one another.
- 5.7
- To sum up, social facilitation is a mechanism by means of which a given
agent updates her knowledge base, including social and pragmatic knowledge, by
observing others, their features and behaviours, and possibly (but not
necessarily) by inferring their mental states.
|
Figure 4. Inputs and outputs of social facilitation
|
Imitation
- 5.8
- In the previous section, social facilitation has been defined and
described as a type of social learning in which the learning agent (O) updates
her knowledge base by perceiving the relationship between another agent (S)
and its physical or social environment. Such relationships may (or may not)
include the effects of S's behaviour on the environment, and/or the effects of
the environment on him (and possibly his achievements). In social
facilitation, O receives information relevant for her current or potential
goals by observing S in a common environment. Consequently, O forms
beliefs/perceptions about S (from which she acquires novel information), but
her goals do not mention S. S simply plays the role of an implicit,
non-deliberate, even accidental indicator or even informant about the
environment.
- 5.9
- In this section, another step of the social learning process is analysed,
namely imitation. Imitation is here defined as a phenomenon of social learning
in which the learning agent is ruled by two social goals concerning S
(a social goal being defined as a goal that mentions another agent's mental
states; cf. Conte
1999):
- Know what S does, how he behaves, how he looks, etc. in order to find
out standards, rules, or simply means to achieve her own goals. O's social
goal is a means for O to reach another goal of hers. The latter might be
specific or generic. For example, O may not know how to use the silverware
in a fancy restaurant. She then looks around to see what her fellows do with
them.
- Adopt S's goals and/or other mental states and possibly the consequent
behaviours, as long as O believes that S is an appropriate or
adaptive model in a given domain. In formal treatment of mental states, a
goal relative (Cohen &
Levesque 1990) to a given belief is a persistent but conditioned goal,
that is, a goal that is pursued as long as it is found neither unfeasible
nor already achieved (persistent) unless the belief associated to it is
revised or retreated (conditioned). In the case of imitation, the goal is
relative to O's social belief: O imitates another agent as long as
she believes that it is useful and convenient to do so, namely as long as
the other shows an appropriate or adaptive behaviour, looks, style under
given circumstances.
Imitation is a behaviour ruled by the goal that
a given agent (O) be-like or act-like another agent M (which stands for
Model), as long as M is (perceived as) a suitable model under a given
circumstance.
- 5.10
- The main difference between social facilitation and imitation is that in
the former case, O has social beliefs about S, from which O obtains relevant
novel information. In imitation, instead, O pursues a number of social goals
with regard to M, relative to her belief that M is a good model. These goals
actually suggest interesting operational criteria for a model of imitation. If
a system is ruled by a goal relative to a given belief (Cohen & Levesque
1990), the system will have to check the truth value of its current belief
- in the case of imitation, it will repeatedly monitor (a) M and his doings,
(b) how good (e.g., adaptive or successful) M is as a model. The relativised
goal is a persistent but conditioned one: in our case, O will persist in
imitation as long as she believes M is a good model.
|
Figure 5. Mental States in Imitation
|
Imitation: Goal-Directed or Goal-Oriented Behaviour?
- 5.11
- The preceding definition might raise a number of important questions: what
types of goals are implied by imitation? What does it mean that O is ruled by
a set of social goals? To what extent can this notion of imitation be used,
which systems can it be referred to? More explicitly, which mental capacity
(or complexity) is required for a system to exhibit and be attributed this
type of behaviour? What is the relationship between Mitchell's (1987) fourth
clause (that behaviour C is designed to be similar to M) and the
definition here provided?
- 5.12
- The question is a difficult one, which will find no conclusive answer
here. Goal-directed behaviour (see Plotkin 1994,
in line with the Piagetian definition) includes goal-governed behaviour (cf.Conte &
Castelfranchi 1995: 8). A goal-governed behaviour is one selected by the
evolutionary process to achieve a given effect, without this effect
being necessarily represented as an explicit goal in the performing agent's
mind. Consequently, imitation among some species might have been selected as
one agent's monitoring of given others (e.g., parents) in order to
be-like or act-like them as long as they are (perceived as) good
models under given circumstances. What is a good model in evolutionary
terms? How can "good" models be biologically transmitted without bringing into
play a sort of Lamarckian evolution? This is a difficult question which
ethological literature can help to answer. For many species, any conspecific
has been selected as a good model (read, better than a non-conspecific) at
least relative to given types of behaviour (e.g., dietary rules). For other
species and in other behavioural contexts, adults have been selected as "good"
models (infant chimps imitating adults foraging for termites using stalks), or
more specifically "first-perceived" adults (imprinting). To adopt the dietary
preferences of conspecifics, in such analysis, is attributable to imitation if
a set of operational criteria are met. To define these criteria, which
correspond to the relativised goals mentioned above, is beyond the scope of
the present model. However, the notion of relativised goal can contribute to
formulate them. A behaviour governed by a relativised goal is a behaviour
persistent but conditioned to a given belief (that M is a good model).
Imitating (a) different sets of models (e.g., conspecifics Vs parents) in
different domains (dietary preferences vs. problem-solving heuristics) is a
necessary but insufficient criterion. In order to check conditioned
persistence, one should probably (b) check whether the animal persistently
monitors its model (like for example, in imprinting), (c) check whether
imitation is conditioned to the model's success (e.g., abandon a given diet
learned from a conspecifc who then dies).
Why Imitate...
- 5.13
- There are several main reasons for O to imitate M,
- Know what to do: in many (social) circumstances, agents may ignore the
efficient or more convenient procedures, rules, plans to achieve their
goals. Sometimes, they may even ignore which goals can be achieved, or which
activities are feasible or safe, etc. For example, while taking a walk in an
unknown city, I follow the main stream of pedestrians simply because I do
not know where to go to, which neighbourhood is safe enough, etc.
- Comply with social standards and norms. This is very close to social
facilitation in the sense that O observes others to infer information about
the world from their behaviours. But what is characteristic about imitation
is that O is interested not only to find out what the norms are, but also to
see how others react to them, to what extent they keep them into account,
which ones are applied and which ones are instead ignored. By this means, O
learns both relevant information about the (social) world, and
relevant (social) conducts.
- Fulfil given roles. Sometimes, imitation is prescribed. For example,
parents are models that children must follow (this has obvious
biological forerunners, such as imprinting).
- Compensate one's inadequacy, ignorance, inexperience in problem solving.
If I do not know how to use the chopsticks, I will probably take the
customers of a Chinese restaurant, or my friend Yang, as suitable models to
observe carefully in order to reproduce their behaviours.
- Avoid complex problem solving or risks. Sometimes, I am too uncertain
about the consequences of a given conduct, and rather than sustaining the
cost of a direct experience, I decide to shelter under someone else. For
example, if I am alone, I may stop on the edge of a slope, but I may risk to
follow someone who decides to proceed.
- Reduce social distance. At times, people imitate others to conform to
them, thereby reducing the social differences within the group. In these
cases, O's goal to adopt M's goals, preferences and behaviours is not
relativised to her belief that M is an appropriate model, but rather to her
belief that M persists in having those goals, preferences, etc. In its most
extreme form, this leads to O following M whatever he does.
- Share responsibility, commitment, etc. and their costs. In social impact
theory, a crucial factor of explanation of bystanders' intervention in
emergencies is precisely the existence of other bystanders. Indeed, the more
they are, and the less cohesive the group, the less efficient or timely the
intervention of bystanders during emergencies. Why? As Latané and Darley (1970)
convincingly explained, people want to share the responsibility of both the
decisions involved (whether or not to define the episode as an emergency,
and whether or not to intervene) with others. No one wants to find herself
in a "vulnerable", isolated, position. Consequently, each one checks what
others do and how they react. Of course, this generates a bottleneck: each
waits for another to make the first move, which no one will then undertake.
- 5.14
- Generally speaking, imitation appears as a short-cut in problem solving
and planning. O minimises the costs[7] she should
otherwise invest in these activities by accepting others' outputs. Of course,
a trade-off may be envisaged here: on one hand, O reduces her own costs, on
the other she might increase them by following others' conducts which later
might appear useless or risky. Indeed, imitation implies delegation and
ultimately trust: O implicitly delegates others to do (part of) the job she
should do. She must trust M to some extent. Consequently, imitation leads to
another, intrinsically social type of problem-solving and reasoning: whom to
trust, and about what? How to tell when someone is trustworthy or reliable,
how to tell that his conduct is adaptive and that it is then reasonable to
follow it? To put it otherwise, when do agents perceive themselves as adequate
in problem solving and when, instead, do they prefer to delegate this to
others?
Whom to Imitate
- 5.15
- This question is closely related to the role of trust: O imitates M when
she trusts M. But to what extent should she trust him, with regard to which
competencies or characteristics?
- 5.16
- First, imitation may have more or less domain-specific target. This is
because trust is relative to specific contexts and domains of competence: I
will certainly look at Yang in using chopsticks, but may have no good opinion
of his command of the English language and therefore refrain from imitating
him in such a context. In addition, imitation may be individualised or not: I
may decide to look at my friend Jenny rather than John, because all
considered, I trust her competence, problem solving capacities, etc., to a
higher extent than I trust his. On the other hand, I may want to look at any
colleague who obtained a promotion in the last two years.
- 5.17
- Another important dimension, which is related to trust but different from
it, is the goal of imitation: a youngster will feel more likely to find models
in her own age cohort than in others. Here, the goal is not problem-solving
but reducing one's social distance from a given social aggregate. Therefore,
the target of imitation is any agent who is a good representative, a typical
exemplar of that aggregate. Obviously, prototypes are trusted to
possess the characteristics which are essential to the category of reference.
- 5.18
- Finally, imitation may be based upon observable frequencies: in many
cases, the more frequent a given behaviour and the more it is target of
imitation. This has at least three reasons:
- the more frequent a given behaviour, the more it is perceived as
rational, in the sense of independent of subjective, idiosyncratic
preferences and biases
- the more frequent a given behaviour and the more it is perceived as one
which as proved to be the fittest (selected by success)
- the more frequent a given behaviour and the more it is perceived as
prescribed, or even mandatory.
... and What to Imitate
- 5.19
- Unlike the classical view of imitation as a strictly behavioural notion,
imitation is here seen as a special case of intelligent social behaviour, in
which the Observer intends or is designed (to use Mitchell's phrase) to be
similar to a given Model, by adopting M's
- Behaviours; here, it is important to recall that imitation does not
necessarily mean to learn a new set of "movements", but rather learn to give
a new meaning (and also a new context) to a given behaviour. As Laland &
Odling-Smee (1999: 6)
observe, by referring to Heyes (1995), "... it
is not the motor pattern that is learned, but rather existing
topographically defined behavioural elements, alone or in
combination, are associated with the consequences of the behaviour,
in a particular context" (italics are ours). More explicitly, in imitation,
agents learn to adapt their behaviour to achieve new goals.
- Internal states, including the mental ones, such as beliefs, values,
preferences (think of the dietary preferences among rats), goals, practical
heuristics (think of the washing of sweet potatoes among Japanese
macaques,Heyes
& Galef 1996). Internal states should not be confused with internal
behaviours, that is, mental actions[8] and
operations, although these may also be targets of imitation.
- Skills; think of Goodall's (1964)
well-known example of the skills necessary for foraging for termites using
stalks acquired by infant chimps imitating adults.
- External standards and criteria, which are inferred to (i) input M's
behaviour, (ii) be mirrored in M's behaviour, and (iii) rule it. The things
that are imitated are (either learned cognitively or selected via biological
evolution) relevant to agents' adaptation. Such relevance assumptions are
essential if imitation (1) is to be at all possible and (2) will combine
efficiency with effectiveness.
How to imitate
- 5.20
- The mental process required by imitation is variable and ranges from the
blind reaction of a baby duck following the first mobile object occurring in
its perceptive field (which may happen to be an ethologist rather than its
mother) to a much more complex set of mental operations and representations.
- 5.21
- In the case of imprinting, the mental properties required by imitation are
rather poor, since the difficulties have been somehow managed at the
evolutionary rather than at the individual level. In other words, the
mechanism is not based upon the single agent's mental representations nor
allowed by its reasoning capacity. Rather, during the evolution of the species
the evolutionary process has gradually selected a sensory-motor schema which
allows the individual animal to answer adaptively some questions crucial for
its own survival.
- 5.22
- In most examples of imitation, and quite often among human adults,
imitation requires instead a rather complex set of cognitive[9]
representations and processes:
- Social beliefs, i.e. (i) information about M, his social status, mental
states, etc.; (ii) information about M 's credibility, reliability,
expertise, etc.. Imitation implies trusting M (or a set of agents, possibly
coinciding with the whole social environment) as a source of information
about adaptive behaviour (for an analysis of trust, see Castelfranchi
& Falcone 1998). However, the extent to which trust promotes
imitation is variable.
- Social reasoning, that is the capacity to infer M's goals, beliefs,
values, etc. from his behaviours or appearance.
- Relativized social goals, i.e. both the goal to acquire information
about M and the goal to be similar to him, as long as he is believed to be a
suitable model.
Advantages of the present analysis
- 6.1
- Since imitation may be displayed even on the ground of built-in schemata
and reactive behaviour, what is the use of a cognitive model as one presented
in this paper? This question is even more crucial if one does not aim only at
describing imitation among natural organisms, but also at implementing
imitation in artificial systems. If there is a way to obtain the same result
with low-complexity mechanisms (such as routines and production rules), why
then bother with high-complexity, cognitive mechanisms?
- 6.2
- There are several answers to this question, both at a scientific level and
at the level of agent and multi-agent systems applications.
To improve scientific understanding of social learning
- 6.3
- It is yet unclear what can be learned via simpler mechanisms, to what
extent social learning can be effectively achieved thanks to simpler
mechanisms at the level of the agent.
- 6.4
- Certainly, a model of imitation that does not account for its cognitive
ingredients will hardly enable us to distinguish social learning from pure
social contagion. The main difference between these phenomena seems to reside
precisely in the role played by the agents' mental processes in each of them:
in social contagion, a given behaviour spreads automatically and easily, and
often as quickly it decays. In social learning, modifications of the agent's
states or behaviours are more robust and durable. The question is how such a
difference can be explained and somehow reproduced. Classic social
psychological theories of social propagation and social learning, including
the priming hypothesis, did not point to one fundamental cognitive capacity
that differentiates contagion from social facilitation and both from
imitation, and that is the capacity to represent the others' minds into one's
own, and reason upon such representation.
- 6.5
- Moreover, cognitive ingredients allow us to give more adequate and
complete accounts of different forms of social learning, e.g., social
facilitation and imitation. Indeed, a low-level definition of imitation as a
mere behavioural phenomenon does not do justice to the ethological evidence
that only animals like apes and dolphins do exhibit imitation, while many
others exhibit only simpler types of social learning, such as social
facilitation, if any at all. Why should this be the case if imitation were
essentially based upon mechanisms such as matching between kinesthetic and
visual images, enough elementary, or simple, to be executed by members of
lower-level species?
- 6.6
- Finally, a cognitive model allows for an evolutionary, or at least a
stepwise view of social learning and intelligence. It allows for different
degrees and types of social influence to be investigated and some forerunners
of social reasoning (reasoning upon others' minds) to be identified. For
example, the capacity to use others as environmental bookmarks requires, and
therefore gradually evolves into, the capacity to map the environment by
deconstructing how others behave in it. As a consequence, certain forms of
social facilitation may require as complex mental processes as those involved
by imitation. But it is also the case that imitation represents an evolution
of the processes involved in more elementary forms of social learning.
Socially intelligent agents for technological applications
- 6.7
- Technological applications in the field of agents require more
sophisticated models of interactive and social competencies (for an
argumentation of this claim, see Conte 1999). In
particular, the necessity to improve agents' capacity to learn from one
another is largely shared by agent systems scientists. Attempts at
implementing this capacity often draw upon classifier systems, adaptable
agents, etc. Two orders of questions arise here:
- How far can one go with the behavioural model of learning allowed by
current solutions, such as classifier systems; on the other hand, what are
the advantages for agent systems' applications of implementing intelligent
social learning?
- More crucially, which properties are needed at the level of the agent to
implement intelligent social learning?
Why implement intelligent social learning
- 6.8
- Current learning systems are essentially stimuli-response systems, either
symbolic (e.g. Learning Classifier Systems) or sub-symbolic (e.g. neural
nets).
- 6.9
- Evolutionary Reinforcement Learning, Classifier Systems used for adaptive
agents (Holland
1992), allow the acquisition of new (social) beliefs, and the emergence of
new strategies and agents. Whilst these systems actually implement learning
and evolving mechanisms, and have allowed to study the emergence and spread of
interesting social phenomena, they do not yet allow to implement:
- The acquisition of attitudes, preferences, and other non-behavioural
features, which implies that these be implemented at the level of the model,
and, moreover, that they are recognised ad interpreted by the learning
agents.
- Selective learning and resistance to change: how to implement at the
level of the agent, given criteria for learning (learning what is desirable,
fair, respectable, etc.)? This is essential to preserve some degree of
system's robustness, and provide the agents with a relative capacity and
criteria for resisting external, namely social influence. On the other hand,
it allows to implement selective learning, and "desirable global effects" to
emerge and spread. Selective social learning is essential to implement the
spread of social norms and conventions in multi-agent systems.
- Social models: these represent an interesting criterion of selective
learning, and therefore a mechanism enforcing conventions and social norms,
in which given others (the so-called significant others) are assumed as
good, convenient, reasonable, respectable, etc. models for imitation. As an
additional advantage, to implement social models would promote the
agent-based simulation study of the emergence of social hierarchies and
structures (such as coalitions, alliances, etc.).
- Different attitudes towards learning: natural agents vary as to their
capacity for and attitude to learning. To implement learning variety is
essential to several domains of agent systems applications (believable
agents, synthetic actors, multi-agent systems, etc.), and requires a model
of the processes and mechanisms that lead agents to want to learn.
How to implement intelligent social learning
- 6.10
- To fulfil the tasks listed above, agents need to
- acquire social mental representations, that is social beliefs and social
goals and intentions, including the goal to imitate others, as well as the
capacity to
- attribute external and internal features to others, and update or
instantiate models of others
- reason upon social beliefs, thereby generating new beliefs and take them
into account while acting and imitating,
- form relativised social goals, that is social goals relative to social
beliefs
- compare one's own knowledge base with that of others
- decide whether to imitate, solving potential conflicts goals among the
goal to imitate and not to imitate, according to some criterion
- adopt external criteria for selective imitation (e.g., social
desirability)
- decide which agents to imitate, instantiating social models to existing
exemplars.
Summary
- 7.1
- In section 2,
some requirements of an adequate treatment of social learning were identified
and found still wanting in the current models. The analysis presented in this
paper seems to contribute to meet those requirements.
- 7.2
- Both a core notion of social learning and some specific notions relative
to the main processes leading to it - social facilitation and imitation - have
been provided, which allowed both the similarities and the differences between
these processes to be emphasised. This analysis presents two main
characteristics:
- A general phenomenon of acquisition of new information has been
addressed.
- Rather than grounding social learning on social reinforcement, social
cognitive properties and mechanisms have been investigated, which seem to
account for both the similarities and the specificities of the two
phenomena of interest.
- 7.3
- Finally, the utility of the approach presented here has been examined at
both the scientific level and at the level of agent system applications.
Acknowledgments
- The authors wish to thank the participants in the AISB '00 workshop on
"Starting from Society" for their useful comments on the draft of this paper
presented there, as well as the anonymous reviewers of JASSS for their
precious suggestions. This work has been partly funded by the EC Fifth
Framework Project "FIRMA" and partly by the EC Fifth Framework Project
"HALFEBIITE".
Notes
- 1 Another important phenomenon is social
control, by means of which agents influence one another to comply with
intra-groups norms.
2 Neither social facilitation nor imitation do
necessarily lead to the agent's acquisition of novel information: the former,
as often found in the social psychological literature, may lead to improved
performance (in simple tasks) and goal emulation. The latter, especially when
aimed to reduce social distance and increase conformity, may lead to comply
with standards and norms already acquired by the agent.
3 We are grateful to one of the anonymous
reviewers of a preceding version of this paper, for having drawn our attention
to this aspect of Bandura's work.
4 In addition, the social release theories
appear to be based upon a rather unwarranted assumption, namely that any
behaviour that is not executed is inhibited or restrained, and that the social
contagion allows for restraint release.
5 Social psychologists (see for example Zajonc 1965)
refer to a rather restrictive notion of social facilitation, conceived of as
the impact of the social context on the quality of one's performance. Thanks
to such an impact, a given agent performs differently (better in simple tasks
and worse in complex tasks) when she is exposed to others performing the same
behaviour. Again, according to this definition, social facilitation is based
upon emulation and social comparison processes.
6 In the remaining of the paper, explicit
reference will be made to human agents to facilitate the reader's
understanding of the reference of pronouns (O will be a female agent, and S
will be a male agent). However, some, if not all the processes analysed may
occur among non-human organisms and even among non-natural systems.
7 The occurrence of a cost minimising strategy
does not indicate that a RAT (Rational Action Theory) approach to agent model
is proposed here. Cognitive action differs from rational action even though it
may be, and often is, self-interested. The main difference is in the internal
factors which account for action. RAT models agents in quantitative terms,
ordered preferences and consequent utility function. Cognitive science models
action in qualitative terms, symbolic representations and rules.
8 To be noted, a mental state should not be
meant as an action accomplished on the brain (e.g., the excitation of the
amygdala: we are indebted to one of the anonymous reviewers of a preceding
draft of the paper for this example). A mental action is here meant as an
action accomplished on internal representations. Of course, mental states can
be induced by non-mental actions. Anxiety or fear may be induced by drugs
ingestion, for example. However, influence, in this sense, is by no means
cognitive, but a merely objective effect.
9 These are cognitive not because they are
labelled as such, but because they need cognitive ingredients and
competencies. Cognitive ingredients are symbolic representations. Cognitive
competencies are the capacities (rules, in computational terms) to manipulate
them. To program a system that imitates others in the sense intended here, one
must feed the system with symbolically represented data and with the rules for
updating them thanks to new data acquired by reasoning about others' minds.
10 This name is after Searle's (1995) example
of the prompt flight of participants at an out-doors party at the first
evidence of an incipient shower.
11 This example was shown to me by my colleague
Cristiano Castelfranchi.
12 This is also known as the "arena" effect: if
during the performance, people in the first rows stand up, those who are right
behind are automatically induced to follow their behaviour, and so on and so
forth until people occupying the farthest seats.
References
- BANDURA A (1977). Social Learning Theory.
Englewood Cliffs, NJ: Prentice-Hall.
BANDURA A (1986) Social Foundations of Thought
and Action: A Social Cognitive Theory. Englewood Cliffs, NJ: Prentice
Hall.
BERKOWITZ L (1973) "Words and symbols as stimuli
to aggressive responses", in Knutson J (ed.), Control of aggression:
Implications from Basic Research, 113-143. Chicago: Aldine-Atherton.
BERKOWITZ L (1984) Some effects of thoughts on
anti- and prosocial influence of media events: A cognitive neoassociationist
analysis. Psychological Bulletin, 95, 410_427.
BERKOWITZ L (1986). Situational influences on
reactions to observed violence. Journal of Social Issues, 42(3),
93-106.
BLACKMORE S (1999) The Meme Machine.
Oxford: OUP.
CASTELFRANCHI C and Falcone R (1998)
"Principles of Trust for Multi-Agent Systems: Cognitive Anatomy, Social
Importance and Quantification" Proceedings of the International Conference
on Multi-Agent Systems (ICMAS 98), Paris, La Villette, July 1998.
COHEN P R and Levesque H J (1990)
"Persistence, Intention, and Commitment", in Cohen P R, Morgan J,
Pollack M A (Eds), Intentions in Communication, 33-71. Cambridge, MA:
MIT Press.
CONTE R and Castelfranchi C (1995) Cognitive and
Social Action. London: UCL Press.
CONTE R (1999), "Social Intelligence Among Autonomous
Agents", Computational and Mathematical Organization Theory,
forthcoming, 1999.
FREEDMAN J L and Perlick D (1979) Crowding,
contagion and laughter. Journal of Experimental Psychology, 15:295-303,
1979.
GALEF B G Jr (1996) "Social enhancement of food
preferences in Norway rats: A brief review". In Social Learning in Animals:
the Roots of Culture. Heyes C M and Galef B G jr. (eds), New York:
Academic Press, 49-64.
GOODALL J (1964) Tool using and aimed throwing in a
community of free living chimpanzees. Nature, 201, 1264-1266, 1964.
HEYES C M and Galef B G jr. (1966) (Eds.) Social
Learning in Animals: the Roots of Culture. New York: Academic Press.
HEYES C M (1995) Imitation and flattery: A reply to
Byrne and Tomasello. Animal Behaviour 50, 1421-24, 1995.
HINDE R A and Fisher J (1951) Further observations on
the opening of milk bottles by birds. British Birds, 44, 393-396, 1951.
HOFFMAN M L (1975) Altruistic behaviour an the
parent-child relationship, Journal of Personality and Social
Psychology, 31, 937-943, 1975.
HOLLAND J 1992. Adaptation in Natural and
Artificial Systems. University of Michigan Press, Ann Arbor, MI.
LALAND K N and Odling-Smee J (1999) The Evolution of
the Meme. Paper presented at the Conference "Can Memes Account for Culture?",
Cambridge, UK, 4-5 June, 1999.
LATANÉ B and Darley J M (1970) The unresponsive
bystander: Why doesn't he help? New York: Appleton.
LEVY D A and Nail P R (1993) Contagion: A theoretical
and empirical review and reconceptualization. Genetic, Social and General
Psychology Monographs, 119:235-183, 1993.
MARSDEN P (1998) Memetics and Social Contagion: Two
Sides of the Same Coin? Journal of Memetics - Evolutionary Models of
Information Transmission, 2, 1998.
(http://www.cpm.mmu.ac.uk/jom-emit/1998/vol2/marsden_p.html )
MARSHALL G (1994) (ed.) Concise Oxford
Dictionary of Sociology. Oxford: OUP.
MITCHELL R W (1987) "A comparative-developmental
approach to understanding imitation". In Bateson P P G, Klopfer P H (Eds.),
Perspectives in ethology, vol. 7: Alternatives, 183-215, New York:
Plenum Press.
PHILLIPS D P (1974) "The influence of suggestion
on suicide: Substantive and theoretical implications of the Werther effect".
American Sociological Review, 39:340-354, 1974.
PHILLIPS D P (1982) "The impact of fictional
television stories on U.S. adult fatalities: New evidence on the effect of the
mass media on violence". American Journal of Sociology, 87:1340-1359,
1982.
PHILLIPS D P (1983) "The impact of mass media
violence on U.S. homicides". American Sociological Review, 48:560-568,
1983.
PLOTKIN H (1994) Darwin Machines and the Nature
of Knowledge. London: Penguin.
REBER A S (1995) The Penguin Dictionary of
Psychology (2nd ed.). London: Penguin.
RITTER E H and Holmes D S (1969) Behavioral
contagion: Its occurrence as a function of differential restraint reduction.
Journal of Experimental Research in Personality, 3:242-246, 1969.
SEARLE J (1995) The Construction of Social
Reality. London: Penguin.
TUOMELA R and Bonniver-Tuomela M (1997) "From
Social Imitation to Teamwork". In Holmström-Hintikka G, Tuomela R (Eds)
Contemporary Action Theory. Vol. II. 1-47. Amsterdam: Kluwer.
VISALBERGHI E and Fragaszy D (1999) "Do monkeys
ape?" Ten years after. Paper presented at the Workshop on "Imitation in
Animals and Artifacts".
WHEELER L (1966) Towards a theory of behavioural
contagion. Psychological Review, 73:179-192, 1966.
ZAJONC R B (1965) Social Facilitation.
Science, 149:269-274
-
|
List A |
List B |
|
"Black-out" effect, or restriction of the space of possible
actions. Here, no social competence operates, but a high regularity, or
convergence, in agents' (social) behaviour due to some central
extraordinary event. No mutual influence is exercised by the agents
undergoing this effect. Still, they converge on the same behaviour (as
happens in explosion of the birth rate nine months after a real
black-out) thanks to a severe restriction of feasible actions.
|
The social models' influence. The propagation of mental
anorexia among young women in Western societies is often considered as a
consequence of their exposition to the unhealthy aesthetic standard of
the "slender type". Of course, this does not account for the intrinsic
replication success of the aesthetic standard in question (which is a
memetic effect), but accounts for the width of the phenomenon: young
women are strongly and widely influenced by it because fashion models
and top girls are skinny. (This belongs to the same category of
phenomena observed by Phillips
1982, 1983 in
his studies on the impact of media on social violence). |
Direct exposition, or the "party-shower" effect[10].
After the 1997/98 repeated earth moves in Central Italy, people were
reported to develop compulsory paranoid thoughts. The same can be
expected to be reported by the Turkish or Taiwan population after the
more recent earthquakes in those areas. As in the black-out effect, a
major discontinuity had been introduced in their normal life by a
non-ordinary event. But unlike the previous effect, in this case, the
influence of this event on agents is determined by their perception and
interpretation of the event, and by the consequent feeling of
powerlessness. However, neither influence nor imitation are
(necessarily) at stake: agents did not need to communicate to, nor
observe, one another (although, in fact, they most certainly did) for
their feelings and behaviours to spread over the whole group.
|
Socially-based goal-activation. Consider Weber's famous
example discussed by several authors (for one example, Tuomela
& Bonniver-Tuomela, 1997): while walking in the street you
realize that people around you have opened their umbrellas. You then
almost certainly infer that it is raining, although your thick hair or
wide hat prevented you from perceiving the first drops. This inference
will activate a goal of yours, i.e. not to get wet. Once such a goal has
been activated, the role of the input agents stops. You are able to find
a solution on your own: if you have an umbrella (which is already stored
in your knowledge base as a good means to avoid getting wet), you will
probably follow the example of your neighbours. But if you were not so
mindful as to get one, you may decide to hasten your pace, or stop at
the next pastry shop, or finally change your mind and get back on your
steps. In all these cases, your decisions are influenced by your
interpretation of the perceived passengers, but only in the former you
actually replicate their behaviours (opening the umbrella). |
Behavioural "domino" effect. With this type of effect, we
enter in a more interesting sub-area of phenomena, namely transmission
(and possibly convergence) due the non-mental effect of agents'
behaviour on, and through, one another. Consider the case in which, in
social or public settings (for example, a crowded restaurant[11]),
you are obliged to raise your voice otherwise your friends won't be able
to hear you. Here, agents do not form any representation of the others
nor of their behaviour. They simply raise their voice in order to be
audible, thereby causing a corresponding continuous increase of
noise[12]. |
Elite-oriented conformity. In this case, agents are ruled by
their goal to show the same taste and preferences as those shown by
(significant) others. They will exhibit given tastes and standards as
long as they believe that these are shared by their models.
Interestingly, this is complementary to the Simmel effect, shown
by agents who consider themselves as "élites": these have the goal of
maintaining preferences as long as these are shared only by their
affiliates. As soon as others will converge on the same preferences, in
order to be perceived as affiliates to the élite, the elitarian agents
will drop them and turn to other, more selective, ones; and the process
will be re-initialised. |
The "vulnerable position" effect. On the highway, if
everybody exceeds the speed limit, you are obliged to break the rule in
order not to be hit sooner or later from behind. Your behaviour is
influenced by the frequential norm established by others. However,
neither imitation nor any representation of the other is (necessarily)
involved. This is a mere case of an emergent regularity (which results
in violating a specific norm). |
The witness effect (or social impact). The famous
Social Impact Theory (Latané &
Darley, 1970) accounts for an interesting variant of the vulnerable
position effect in groups of agents facing an emergency. To avoid an
isolated and therefore "vulnerable position", each bystander waits for
someone else to make the first move and provide help to the victim. As a
consequence, no-one will provide the help required. |
Automatic contagion of emotion expression. At a party, if one
starts to yawn, s/he will most certainly be followed by many
participants. If you happen to listen to some foreigners speaking in an
incomprehensible language and to see them bursting into laughter, you
can't help laughing as well. If asked why you were laughing, you won't
be able to give any good reason; still the automatic impact of laughter
is irresistible. |
Emotional sharing. Consider the case of empathy (cf.
Hoffman
1975). In this phenomenon, emotion spreads thanks to a specific
mental process. A beggar shows helplessness and even despair because he
is helpless (he believes something like "How dreadful: I am
helpless"). The empathic passenger will feel sad if she believes "How
dreadful: he is helpless". However, thanks to the empathic
mechanism (rather mysterious, indeed, in absence of some biological
source of solidarity), the passenger shares (to some extent and for a
short time) the emotion or feeling expressed by the beggar. Here,
something new occurs: the passenger perceives the emotional state of the
beggar and infers his/her more general (social) state: empathy is in
fact based upon specified attributions. In fact, people do not share the
feelings of those who are perceived as responsible for their mishaps.
Only under given attributions, they come to share the feelings of the
victim. The emotional sharing is therefore caused by an inferential
process, by a reasoning applied to the mental and objective conditions
of the victim. However, no imitation occurs yet.
|
|
Return to Contents of this issue
©
Copyright Journal of Artificial Societies and Social Simulation, 1999