Variation is the universal: making cultural evolution work in developmental psychology

TLDR

Culture is a human universal that introduces variation in psychology, behavior, and development, yet developmental research has historically underemphasized cultural and contextual factors, especially outside affluent Western societies. The paper aims to expose four common false assumptions in developmental psychology that undermine the quality of both standard and cross‑cultural research. The authors identify and critique four assumptions—universality, Western centrality, deficit, and equivalency—using cultural evolutionary theory to propose theoretically grounded alternatives. Drawing on positive examples, the authors argue that incorporating culture and expanding participant pools will yield a more inclusive and accurate account of human development. This article appears in the theme issue “Bridging cultural gaps: interdisciplinary studies in human cultural evolution.”.

Abstract

Culture is a human universal, yet it is a source of variation in human psychology, behaviour and development. Developmental researchers are now expanding the geographical scope of research to include populations beyond relatively wealthy Western communities. However, culture and context still play a secondary role in the theoretical grounding of developmental psychology research, far too often. In this paper, we highlight four false assumptions that are common in psychology, and that detract from the quality of both standard and cross-cultural research in development. These assumptions are: (i) the universality assumption , that empirical uniformity is evidence for universality, while any variation is evidence for culturally derived variation; (ii) the Western centrality assumption , that Western populations represent a normal and/or healthy standard against which development in all societies can be compared; (iii) the deficit assumption , that population-level differences in developmental timing or outcomes are necessarily due to something lacking among non-Western populations; and (iv) the equivalency assumption , that using identical research methods will necessarily produce equivalent and externally valid data, across disparate cultural contexts. For each assumption, we draw on cultural evolutionary theory to critique and replace the assumption with a theoretically grounded approach to culture in development. We support these suggestions with positive examples drawn from research in development. Finally, we conclude with a call for researchers to take reasonable steps towards more fully incorporating culture and context into studies of development, by expanding their participant pools in strategic ways. This will lead to a more inclusive and therefore more accurate description of human development. This article is part of the theme issue ‘Bridging cultural gaps: interdisciplinary studies in human cultural evolution’.