The 89th Annual Meeting of the American Association of Physical Anthropologists (2020)


Tool specialization in human cultures: modeling the effects of demography and environmental change on cultural repertoire size

SARAH SAXTON STRASSBERG1, OREN KOLODNY2 and NICOLE CREANZA3.

1Biological Sciences & Medicine, Health, and Society, Vanderbilt University, 2Department of Ecology, Evolution, and Behavior, A. Silberman Institute of Life Sciences at the Hebrew University of Jerusalem, 3Biological Sciences, Vanderbilt University

April 16, 2020 , Platinum Ballroom Add to calendar

For millennia, behaviorally modern humans have participated in task specialization for biological, socioeconomic, and cultural reasons. However, humans are not alone in this regard; Neanderthals likely specialized, and some bees, ants, fish, and spiders delegate tasks to certain groups of individuals. Many studies suggest that specialization is a crucial aspect of technological advancement. However, if tools or skills known by few individuals are more likely to be forgotten, specialization also creates a paradox in which innovation is more common but specialized innovations may have a higher probability of being lost. In this study, we build on a computational model (Creanza, Kolodny, Feldman J. Roy. Soc Interface 2017) to examine the varying levels and types of task specialization in human populations (guild-like groups, division of labor by sex, etc.). We then assess when these types of specialization are beneficial, neutral, or deleterious to a population’s overall tool repertoire size in relation to the output of generalist populations. We find that environmental change is detrimental to tool repertoire complexity, regardless of level of specialization, but when there are one or more specialized subpopulations present, environmental change inhibits tool accumulation more than it does in a generalist population. In addition, we find that increased relative size of specialized subpopulations leads to decreased overall tool repertoire size. A high tool loss rate is also detrimental to specialized populations’ productivity, whereas a high tool innovation rate is critical to specialized subgroups’ success. These results elucidate the mechanisms of the evolution of specialization in human populations.


Slides/Poster (pdf)