Macro-evolutionary studies of cultural diversity: a review of empirical studies of cultural transmission and cultural adaptation

Abstract

A growing body of theoretical and empirical research has examined cultural transmission and adaptive cultural behaviour at the individual, within-group level. However, relatively few studies have tried to examine proximate transmission or test ultimate adaptive hypotheses about behavioural or cultural diversity at a between-societies macro-level. In both the history of anthropology and in present-day work, a common approach to examining adaptive behaviour at the macro-level has been through correlating various cultural traits with features of ecology. We discuss some difficulties with simple ecological associations, and then review cultural phylogenetic studies that have attempted to go beyond correlations to understand the underlying cultural evolutionary processes. We conclude with an example of a phylogenetically controlled approach to understanding proximate transmission pathways in Austronesian cultural diversity.

Figure 1.

Estimation of phylogenetic nearest neighbours (NNs). The NN for each culture is either a tip or a node: for Samoan it is Tongan, for Javanese it is Balinese and for Malay it is the internal node indicated by the grey filled circle. The state of each tip was available from the ethnographic data, while the state of the trait at the internal node was calculated using the maximum-likelihood method of Discrete [56,57]. We obtained a probabilistic estimate that the trait was state 0 or 1, using an explicit model of evolution and the information on branch lengths contained in the phylogeny. The presence of the trait was only assumed when 100 maximum-likelihood tries provided an average likelihood over 70% that the trait was state 0 or 1. If the method was unable to provide an estimate of a society's PNN for any trait, that trait was not examined for that society. This is a conservative measure that takes into account the uncertainty in reconstructing the node on the phylogeny.