royalsociety | The Neolithic was marked by a transition from small and relatively
egalitarian groups to much larger groups with increased
stratification. But, the dynamics of this remain
poorly understood. It is hard to see how despotism can arise without
coercion,
yet coercion could not easily have occurred in an
egalitarian setting. Using a quantitative model of evolution in a
patch-structured
population, we demonstrate that the interaction
between demographic and ecological factors can overcome this conundrum.
We
model the coevolution of individual preferences for
hierarchy alongside the degree of despotism of leaders, and the
dispersal
preferences of followers. We show that voluntary
leadership without coercion can evolve in small groups, when leaders
help
to solve coordination problems related to resource
production. An example is coordinating construction of an irrigation
system.
Our model predicts that the transition to larger
despotic groups will then occur when: (i) surplus resources lead to
demographic
expansion of groups, removing the viability of an
acephalous niche in the same area and so locking individuals into
hierarchy;
(ii) high dispersal costs limit followers' ability
to escape a despot. Empirical evidence suggests that these conditions
were
probably met, for the first time, during the
subsistence intensification of the Neolithic.
