Genes, Brains, and Human Potential The Science and Ideology of Intelligence

244 POTENTIAL BETWEEN BRAINS

between the individual dynamics and the interaction dynamics, and

nonlinearities in the confi guration space.”^7

DOMINANCE HIERARCHIES

Of course, forming shoals or schools is not the only form of social be hav ior
in fi sh. Even in loose aggregates, individuals learn from the successes and
failures of others in such activities as food foraging, nest building, and
route fi nding (this is called “observational learning”). Perhaps the most
obvious social formation in at least some species of fi sh (as well as other
animals) is the dominance hierarchy. In such groups individuals are clearly
diff erentiated in a way that regulates priority of access to food, mates, or
other resources. Studies of such hierarchies have been revealing.
Deterministic models have generally assumed that rank status is due
to some individual attribute, such as size, aggressiveness, superior genes,
physiology, or other indication of “biological fi tness.” Experiments by
Ivan Chase and colleagues, however, question that idea. Th ey brought
groups of fi sh together in a tank to form a hierarchy. Th e fi sh were then
separated for a time before being brought back together again. In those
reunions of exactly the same fi sh quite diff er ent hierarchies tended to
form. Although individual attributes did seem to have a minor role,
social dynamics seemed to be much more impor tant.^8 Th is result is
confi rmed by other studies in a wide range of species.
Such fi ndings suggest that social hierarchies are self- organ izing, self-
structuring, dynamical phenomena. Th eir function may be that of reduc-
ing uncertainty in social access to resources, where “queuing” is more
mutually benefi cial than a scuffl e. As Chase and colleagues glean from
further research, be hav ior is highly context dependent and is conditioned
even by numbers in the group. Individual attributes have little or no abil-
ity “to predict the outcomes of dominance encounters for animals in
groups as small as three or four individuals.”
Instead, they go on, “We review the evidence for an alternative ap-
proach suggesting that dominance hierarchies are self- structuring. Th at
is, we suggest that linear forms of organ ization in hierarchies emerge
from several kinds of behavioral pro cesses, or sequences of interaction,

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