reputation in evolution

Reputation in Evolution

Rosaria Conte

LABSS/ISTC-CNR

ICORE, Gargonza, Italy

March 18-20, 2009

The problem

How explain cooperation if nonreciprocators are better-off within the group?

Solutions are usually found in social control. But why agents carry on and sustain its costs?

Previous theory (Conte and Paolucci, 2002) defined reputation as reported-on evaluation (human intelligence)

Here, speculations about how this theory of reputation can help in answering that question.

Outline Strong Reciprocity (SR) as one example of social

control. Open questions Tasks in social control Transmission of social evaluations and its impact

on efficiency of social control Social cognitive theory of reputation and expected

impact of reputation transmission on social control Examples of reputation transmission from

ethnographic descriptions Conclusions and questions still open.

Strong Reciprocity

Hypothesis and simulation evidence Since 1999,

Evolutionary GT (EGT) has put forward and tested by means of simulation the idea that the evolution of altruism was made possible in human societies (prehistoric hunterer-gatherers) by

Strong Reciprocators carry out and sustain the costs of punishing nonreciprocators.

From Bowles and Gintis, 2003)

Open questions

Like theory of 2nd-order cooperation (Heckathorn, 1987; Oliver, 1993; Horne, 2007),

SR leaves some questions open: By definition, costs of punishment < costs of

cooperation. Is this true? What about costs of retaliation? Why agents other than victims carry on

punishment?

Tasks in Social Control

Tasks

Identify executors Directly (memory of own experience or

observation of others’) Indirectly (transmission of evaluation)

React Punishment/retaliation Exclusion/isolation

Identify executors Directly (memory of own experience or

observation of others’) Indirectly (transmission of evaluation)

React Punishment/retaliation Exclusion/isolation

Benefits and costs of identification

Direct acquisition of information• Own experience

• Benefits: moderate (insufficient info)• Costs: high (info paid at own expenses)

• Others’ experience (observation; cf. Nowak and Sigmund, 1998 etc.)• Benefits: moderate (wider info but still insufficient)• Costs: low

Indirect: transmission of information • Benefits: very high (much wider info, since one receives information in

return)

• Costs: moderate (lower than own exp., but higher than observation)• Communicative act, assumed to be moderately low and constant • Effect of information spreading to undesirable recipients, • Potential retaliatory reaction to info transmission,

Benefits and costs of reactions Defence/exclusion: avoid bad guys, exclude them from partner

choice and communication. Benefits:

• avoid bad deals• prevent cheaters’ profits from such deals

Costs:• none

Retaliation/punishment (for a distinction, see Andrighetto et al., in prep.): action aimed to damage nonreciprocators. Benefits:

• above + • deterrence

Costs:• act of punishing• further reaction of recipient.

To sum up…

Reactions are as beneficial as costly. Punishment is as efficacious as

expensive, Exclusion is less convincing, but

self-protecting Identification can be optimised

by means of communication.

Spare costs of transmission to optimise social control…

So far, so good. However, communication is not for free

spares the costs of acquiring information, entails the costs of transmitting it

Is it possible to reduce such costs without reducing benefits?

Let see whether reputation, as a specific form of social intelligence, can help…

A Social Cognitive View of Reputation

Types of social evaluations

Evaluations

Image Reputation

Set of evaluative beliefs about a given

target

Meta-beliefs about others’ evaluation

Social cognitive properties of reputation transmission

No personal commitment of speaker about nested beliefs’ truthvalue.

No responsability about their credibility and consequences (“I am told that…”)

Implicit source of rumour Indefinite author of evaluation

Effects on social control

Reporting on beliefs of indefinite source, Prevents the target from providing discharge Denies escape Unfalsifiable accusation Lower costs of reputation transmission for

participants• it can be practised by anyone• prevents escalation of aggression and violence: people are

likely to transmit reputation, because they hidethemselves behind indefinite source

Travels fast (badmouthing faster)• before the victim's innocence is proved, her reputation is spoiled.

Reputation Transmission in Traditional Societies:

An Overview“Anyone who has obeyed nature by transmitting a piece of gossip experiences the explosive relief

that accompanies the satisfying of a primary need”.”

Primo Levi"About Gossip," 1986).

Cooperation or competition?

Reputation transmission = gossip With Gluckman’s study (1963), gossip became an

object of study of its own in cultural anthropology No consistent view (Levinson and Ember, Enc. Cult.

Anth., 1997): Social cohesion (group maintenance; Gluckman, 1963) Social conflict (alliance against, Colson, 1949; etc.).

Shift of focus (Brenneis, 1987; Besnier, 1989; Brison, 1978; etc.), the form of gossip its features, the social characters and relationships involved, and the narrative.

The interactive nature of Fatufatu among the Nakulaelae

Successful Nukulaelae gossips often “pause dramatically at strategic moments” (Besnier, 1989) Waiting for interlocutors’ interjections or

comments on the scandalous content of narrative

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Atoll in Pacific Ocean

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Joint creation of Talanoa in Bhatgaon

Talanoa (tah-lah-NO-ah) is idle talk of Hindu inhabitants from the village of Bhatgaon in Fiji, as described by Donald Brenneis (1978).

Reputation is the kernel of social hierarchy.

Speakers and audience cannot be easily dfferentiated because gossip is created jointly by all participants

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Social relationships in Talanoa

Two relationships: Gossiper towards target:

limit perception of own identity

Gossiper towards gossipers:

• don’t cause sanctions or retaliation

• Let recipients form opinions “of their own”.

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Talanoa Village

Third-person narrative in Talanoa: Bole A requirement of talanoa emerging from

transcriptions is the continuous and repeated use of the word “bole” (lit. the third sing. person of present tense of the verb “to speak”), used to mean “I’ve heard saying” or “they say” refer to an indefinite speaker or source.

In both cases the use of “bole” caused the speaker to keep a distance from what s/he says: s/he is not reporting on his/her own opinion but on voice or rumours.

Ambiguous and indefinite narratives in Talanoa

Talanoa transcriptions cannot be understood without previous knowledge

Heavy use of metaphors, irony, atc., communicating that what is hidden is more than what is said.

Indefinite characters Targets are never clearly identified The authorship of a particular gossip is blurred

Indefinite authorship among the Hopi

Bruce A. Cox (1970) studied gossip in the reservation Hopi in Arizona, 11 villages

Gossip starts when political authority is monopolised by one group.

Powerless use gossip to keep authority under control and form alliances.

Victims cannnot escape effect of accusation since, source is not revealed, evidence is not brought about nor disconfirmed.

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Hopi pueblo in Arizona (1879).

Hopi House near Grand Canyon, 2005

“Just talk” among the Kwanga

In 1992, Karen Brison studied the Kwanga, a tribe of hunterer-gatherers in Papua New Guinea which lives in numerous villages characterised by complex social networks.

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The Kwanga Initiated men form a community

of equals. Attempts to command lead to loss of support.

The Kwanga hold long community meetings to discuss matters of common concern), during which gossip is spread about powerful men:

If asked to produce evidence accusators resort to a conventional solution: they claim theirs was just talk, rumours…...

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To sum up Gossip leaves indefinite

The target (Kwanga) The source (Bole)

Is spread in absence of target (Talanoa) Is unfalsifiable and unaccountable (Hopi) maintains group-values and identity (Makah) but also creates alliance (Hess and Hagen, 2002;

Goodwin, 2002) of underprivileged against luckier prevents retaliation (many) it is fun (Talanoa) deplorable (Fatufatu)

What these features amount to… Impersonal narratives no commitment on truthvalue Indefinite authorship Joint creation of gossip no responsibility indefinite targets

common in small acephalous communities (see also Boehm, 1999), where members are interdependent and act covertly instead of taking direct action which might offend others.

Ethnographic evidene matches the cognitive analysis

Any general conclusion? Gossip is a universal behaviour, with more or less the same

features, but different social consequences Nonsense to look for consistent effects! These are often

prosocial, but sometimes gossip may be used strategically, to create alliances against someone, etc.)

Its universal features converge on transmit a reported-on evaluation (reputation)

Thus Prevents retaliation thus sparing participants both

• costs of info acquisition • costs of transmission

Provides incentive to participate in social control

Further effects Low cost transmission provides incentive to

informational cooperation. Hence, larger informational basin What about material cooperation? No final

answer. Under certain conditions, E.g. Negative and unfalsifiable gossip + consequent exclusion:

• Set of agents said to be bad implies and exceeds set of bad agents

The larger the informational network the lower the number of cheating deals.To be checked by means of simulation!

Further questions Why inherently pleasant?

Perhaps because it is a self-enhancing protected aggression?

Motivations and emotions should be investigated…

Why deprecated? unprivileged and weak use gossip as

their only weapon In natural reasoning, a material

implication becomes an equivalence (Geiss & Zwicky, 1971; Oaksford & Stenning, 1992; Wason & Johnson-Laird, 1972). From, “if p then q”, to “If p then q, and if q then p.”

From “If you are weak, you can only aggress by means of gossip”, to “If you gossip, you are weak.”

Participants in gossip are said to be weak and unprivileged.

Hence, gossip is a vile and self-derogatory practice.

Conclusions Dunbar (1998) and Panchanathan (2001) suggest that

gossip evolved as an adaptive response to a selective pressure towards enlarging hominids’ settlements.

Here gossip is argued to have evolved Taking advantage of a human cognitive capacity By providing incentive to participate in social control because it

lowers its costs keeping constant benefits (spreading meta-evaluation inhibits retaliation).

Data from traditional societies match this suggestion. Enlargement of human societies as a possible side-

effect.

To be done

If deceitful gossiper is not punished, to what extent does social control work? Trade-off between Unfalsifiability of accusation Utility of information

Possibly, there is a threshold above which informational cheating leads to system collapse.

An empirical question for future simulation-based studies.