Norms in Multi Agent Systems.(What about Norms as Such?)

Rosaria Conte

LABSS/ISTC Laboratory of Agent Based Social Simulation, Institute of Cognitive Science and Technology,

CNR, Rome. Italyhttp://labss.istc.cnr.it/

MONTREAL, July 2008

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Outline

SoA In search of unification

A social cognitive view The MAgent based approach. Normative agent

architectures: • BOID• EMIL-A

Simulation model and results Conclusions and future work.

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State of the art

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Norms and the social/behavioral sciences

Nonetheless (or consequently?), norms break down in too specific notions

Archipelago norm includes at least Conventions and social norms Moral norms Legal norms

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Norms are universally present in all human societies (Roberts, 1979; Brown,

1991; Sober and Wilson, 1998); ancient: highly elaborated in all human groups, including hunter-

gatherers and groups that are culturally isolated. ubiquitous. governing all activities, from mate choice to burial Impactful: on welfare and reproductive success.

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Conventions and social norms

From analytical philosophy (Lewis), social sciences derived a conventionalistic view of norms as spontaneously emerging behavioral regularities based on conditioned

preferences enforced by sanctions

Open questions How about mandatory

force (Gilbert, 1993)? How do norms innovate? Why bother with

sanctions, if norms are conditionally preferred?

Why do we violate norms?

How tell norms from behavioural regularities?

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Moral norms From (evolutionary) psychology,

social sciences (but also robotics) derive a view of norms as moral motivations independently of any legal or

social institution (independent normativity; Sripada & Stich, 2005)

based on subjective authority and internalized (intrinsic) motivations

compliance is valued even when there is no sanction from external source (Durkheim, 1968 [1912]; Scott, 1971).

Questions What about

internalization? Do agents keep the normative trace of moral motivations?

Why norm violation? What about unfair norms?

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Legal norms From philosophy of law

and deontic philosophy (Von Wright, Kelsen), logicians and AI scientists derive an imperativistic view of norms as commands Deliberately issued Enforced by explicit

sanctions

How do prescriptions emerge?

How to tell norms from coercion?

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How about a general notion of norm?

legal

moral

socialreligious

What is common to them?

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A requirement for unification“Despite the vital role of norms in human lives and

human behavior, and the central role they play in explanations in the social sciences, there has been very little systematic attention devoted to norms in

cognitive science.” (Sripada & Stich, 2005)

Only such a systematic attention can contribute to an integrated theory of norms.

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Lets try:A social cognitive definition

Norms = behaviors spreading in population (Pi) as long as

Corresponding prescriptions and mental constructs (Conte and Castelfranchi, 1995;2006) spread over Pi

N-beliefs: beliefs that for given sets of agents given wss/actions are obliged/forbidden/permitted

N-goals: goals to (not) achieve/accomplish obligatory/forbidden/permitted wss/actions.

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Cognitive puzzles

– What are obligations?– And prescriptions? – Very tentatively

– Command is supported by a normative belief, – Source (vector) wants (the prescription) to be

obeyed on the grounds of a normative belief– Hence, source (vector) wants recipient to form

a normative belief.

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Properties of norms• Hybrid

behaviour mental construct

• dynamic: undergoing two processes emergence: process by means of which a norm

not deliberately issued spreads through a society

immergence: process by means of which a normative belief is formed into the agents’ minds (Castelfranchi, 1998; Conte et al., 2007)

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Implementing norms on agents MAgent based approach.

Normative architectures The BOID architecture (Broersen et al., 2001).

EMIL-A (from a ICT-funded European project “EMergence In the Loop. The 2-way dynamics of norm-innovation”)

http://emil.istc.cnr.it/

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B

O

I

D

PObsAct

The BOID architecture BDI architecture with

obligations: Beliefs, Desires, Intentions, Obligations.

Interactions at study: which component is overriden? Realism: B override all

others Selfishness: D override

obligations Sociality: O override

intentions.

Why no direct interactions among D, I and O? No trace of the norm in goals

Why O is a separate component? Cognitively implausible…

How are O acquired?

Reproduced from Broersen et al. (2001)

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OTHERWISE

• How acquire norms autonomously?

• How to account for transgression?

• How to account for conflict resolution?

N-action

Norm-recognition

N-Belief

N-Goal

N-intention

EMIL ARCHITECTURE

Decision making

Norm-adoption

N- Board

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N-action

Norm-recognition

N-Belief

N-Goal

N-intention

EMIL ARCHITECTURE

Decision making

Norm-adoption

N- Board

• What about reactive behaviour?

• automated conformity?

• What does it mean?

• Shortcuts are possible

• But, “thoughtless” conformity is semi-automatic:

• Agents can re-gain control over the whole process and

• Perform decision-making

• Finally, what about internalization?

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Norm Recognition

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Input

X a T Y

Each input is presented as an ordered vector Source (x); Action transmitted (a) (potential norm) Type of input:

Behaviors Messages: assertions (A), behaviours (B), requests (R),

deontics (D), evaluations (V), sanctions (S); Observer (y);