Quantitative approaches to kinship terminology evolution

  • Sam Passmore

Student thesis: Doctoral ThesisDoctor of Philosophy (PhD)


Diversity in kinship is higher in humans than in any other species (Chapais, 2009). Human kinship does not only entail reproduction, but divides relatives into categories which convey important, culturally specific information (Jones, 2010; Parkin, 2012). These cultural categories of kin are expressed linguistically in kinship terminology, a system of words for relatives. Despite the variety in how kinship is enacted, some theorists have declared cross-cultural organisation of kinship terminology to be constrained to “very few types … only ten or so” (Godelier, 2012, p 180).

In this thesis, I examine kinship terminology diversity using evolutionary anthropological theory. I applied evolutionary methods to question the universality of existing theories; I developed a global kinship terminology database and projected observed diversity into a morphospace to conceptually and quantitatively test for universal patterns of kinship terminology; and tested cultural-evolutionary predictions of kin categorisation on behaviour.

Chapter 2 used phylogenetically-controlled methods to test eighteen hypothesis between kinship typology and social structure in three language families (Austronesian, Bantu, and Uto-Aztecan), finding little co-evolutionary support between and considerable lineage specific trends. This highlighted the need for rigorous analysis of existing ideas and the lack of diversity captured in the existing typology.

To establish the true extent of kinship terminology diversity, I build (with colleagues) a database of 1,022 kinship terminologies, Kinbank (chapter 3). Using this global sample, I conceptualised a morphospace approach to kinship terminology diversity, named kinspace, incorporating cultural, biological, and cognitive constraints (chapter 4). I then quantitatively approximated kinspace to establish a new typology and proposed theories of terminological change from the common structures (chapter 5).

Beyond the macro- and structural- properties of kinship terminology are how they are enacted by individuals. The chapter 6 found that linguistic categorisation of kin influences cooperative behaviour, by comparing economic decisions between languages with different kin terminology (American-English and Hindi).

This thesis established the importance of evolutionary theory in understanding the relationship between language and social structure; in understanding the constraints on diversity imposed from cultural, biological, and cognitive pressure; and finally exploring the impact of macro-level structures on individual behaviour.
Date of Award21 Jan 2021
Original languageEnglish
Awarding Institution
  • The University of Bristol
SupervisorFiona M Jordan (Supervisor)

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