Santa Fe 2001 breakout group: Simple to complex (Rob P, Mike, Penny, Juergen L, Bob J, Jennifer)

We decided that there are at least two social transitions: from solitary to social, and the loss of reproductive potential, or the transition from hierarchical to distributed organization

Defining a social group

Social phenotypes include nest construction, reproduction, defense, nutrition, brood care

Sociality may not include all of these, but congregations for one behavioral goal are not sufficient.

"If you are together just to reproduce you are not social, and if you are together just to eat you are not social, but if you are together to eat and reproduce you are social"

Step 1 incipient social groups


Reduced dispersal–not emigrating/dispersing

Tolerance–allowing other individual to be there

Sample a common stimulus environment

(variation in initial sensitivity or positive feedback loop?)


Direct or indirect interaction effects

Effect of behavior on environment

Cues from pre-existing products or behaviors

Direct physical/chemical interactions

Consequent attributes

Differentiation in behavior–task specialization

Group cohesion or clustering

Mass action behaviors

Step 2: simple to complex social groups

We use group size increase as an independent variable

Possible emergent Consequences:

Loss of totipotency

Sophisticated communication

Complex nest structure

Increased individual specialization

Increased modularity

Distributed control (via hierarchical control)

Selection induced consequences

Reduction of conflict at inter- individual level

Convergence of interests between reproductive and nonreproductives

Evolved signals

The two main questions:

What is the minimum set of emergent and adaptive properties at the transition from solitary to social, and from simple to complex?

What are the minimal individual behavioral changes necessary for these transitions?

Some relevant hypotheses:

The transition from simple to complex societies involves a transition from emergent

dominance to hierarchical to distributed control

Hierarchy is a mathematical consequence of dominance with increasing n

The absence of hierarchy in simple (communal) groups may be because the groups are

compositionally ephemeral

The emergence of social structure involves the emergence of 3 general properties:

behavioral differentiation (including specialization, dominance and parasitism),

group cohesion and mass action behaviors