Cultural evolutionary theory: How culture evolves and why it matters

Abstract

Human cultural traits-behaviors, ideas, and technologies that can be learned from other individuals-can exhibit complex patterns of transmission and evolution, and researchers have developed theoretical models, both verbal and mathematical, to facilitate our understanding of these patterns. Many of the first quantitative models of cultural evolution were modified from existing concepts in theoretical population genetics because cultural evolution has many parallels with, as well as clear differences from, genetic evolution. Furthermore, cultural and genetic evolution can interact with one another and influence both transmission and selection. This interaction requires theoretical treatments of gene-culture coevolution and dual inheritance, in addition to purely cultural evolution. In addition, cultural evolutionary theory is a natural component of studies in demography, human ecology, and many other disciplines. Here, we review the core concepts in cultural evolutionary theory as they pertain to the extension of biology through culture, focusing on cultural evolutionary applications in population genetics, ecology, and demography. For each of these disciplines, we review the theoretical literature and highlight relevant empirical studies. We also discuss the societal implications of the study of cultural evolution and of the interactions of humans with one another and with their environment. cultural evolution | mathematical models | gene-culture coevolution | niche construction | demography H uman culture encompasses ideas, behaviors, and artifacts that can be learned and transmitted between individuals and can change over time (1). This process of transmission and change is reminiscent of Darwin's principle of descent with modification through natural selection, and Darwin himself drew this explicit link in the case of languages: "The formation of different languages and of distinct species, and the proofs that both have been developed through a gradual process, are curiously parallel" (2, 3). Theory underpins most scientific endeavors, and, in the 1970s, researchers began to lay the groundwork for cultural evolutionary theory, building on the neo-Darwinian synthesis of genetics and evolution by using verbal, diagrammatic, and mathematical models (4-8). These models are, by necessity, approximations of reality (9), but because they require researchers to specify their assumptions and extract the most important features from complex processes, they have proven exceedingly useful in advancing the study of cultural evolution (10). Here, we review the field of cultural evolutionary theory as it pertains to the extension of biology through culture. We focus on human culture because the bulk of cultural evolutionary models are human-centric and certain processes such as cumulative culture seem to be unique to humans. However, numerous nonhuman species also exhibit cultural transmission, and we consider the areas of overlap between models of human and animal culture in Discussion.The study of cultural evolution is im...

Culture extends the scope of evolutionary biology in the great apes

“…7). Such a statement is obviously true for our own species (8)(9)(10)(11); here I examine the justifications for thinking the phrase also has validity for great apes.…”

The extension of biology through culture

“…In contrast to common approaches in cultural anthropology, those working within the field of cultural evolution have created an array of different approaches and methods that are often more conventionally scientific. These include a greater emphasis on such elements as formal and mathematical modeling, quantification and statistical analysis of numerical data, hypothesis testing, and systematic experimentation (18,25,56,(60)(61)(62)(63). There is not the space here to offer anything like a comprehensive review of the resulting discoveries, but we can outline something of their range, with selected illustrations.…”

“…Empirical evidence in support of these contentions has accumulated over recent decades, reviewed for example in refs. 61, 62, 78, 83, and 84, and is pursued further in the present collection (18,63).…”

“…Papers in the earlier parts of the collection have a predominant focus on studies of animals, and the remainder a focus on the human case. These are sandwiched between an opening paper coauthored by one of the founders of the subject of cultural evolution, that offers an overview of core cultural evolution theory and empirical findings across human demography, population dynamics, and ecology (18), and a final complementary overview appraising progress made and prospects for the future of these endeavors (63).…”

“…The present collection of papers opens with a contribution by Creanza et al (18) that offers an overview of both the foundational studies in (human) cultural evolution and major developments in the period since. The early body of 20th century work laid out some of the ways in which cultural evolution: (i) echoes many core principles of organic evolution, yet (ii) also differs from it in dramatic ways that change evolutionary dynamics, and (iii) interacts with the genetically based phenomena to create new complexities ("gene-culture coevolution").…”