Family composition and attitudes


This project investigates whether individuals' gendered fitness interests (GFI) - the fitness stake each participant has in their feminine and masculine kin - explain significant variations in social, political and cultural attitudes, beyond the effects of individual sex alone.    Evolutionary kin selection theory (Hamilton 1964a, b) predicts that behaviour should transcend self-interest and extend to the interests of genetic relatives. This theoretic insight has revolutionised the study of animal behaviour over the last 50 years, and it has had some modest success in explaining human behaviours including nepotism and variation in parental care (Daly and Wilson 2005).    There is some evidence that the sexes of immediate descendant kin can change attitudes to ideologically polarising issues such as abortion and income redistribution. Attitudes to abortion are associated with the number of female kin a person has in the 15-50 age group “at risk” of unwanted pregnancy. Economists have shown that parents of daughters favour gender equity policies more than parents of sons do and US congressmen with daughters vote more progressively regarding reproductive rights, working families and education. Parents of daughters vote more for left-wing parties than do parents of sons, and the birth of a daughter can cause a swing    to the political left, whereas the arrival of a son can do the opposite.

Research Questions / Hypotheses

Does having more male-biased GFI predict attitudes toward gender issues?


80 people took part in the study. Data has not been analysed so no exclusions apply.


Participants will anonymously complete a survey including demographics, family structure and questions concerning attitudes to family and gender roles plus a small number of questions about contemporary events. We aim to look to estimate the magnitude of any effects of GFI on these attitudes.


We operationalise GFI as a function of age, sex, and genetic relatedness. Summed across each individuals' family tree, we determine the numeric index that indicates the degree to which an individual is expecting future reproductive fitness from males or females. We then use this index to predict attitudes toward gender issues.


The research will contribute to our understanding of family and attitudes concerning sex and reproduction as well as inform current literature and research on the topic. The research results will be submitted to academic journals for publication and will be included in presentations for academic conferences. Participant confidentiality will be maintained in reports and publications as no identifying information will be provided in these.