Abstract
Objective
Gendered Fitness Interests (GFI) Theory posits that the sex of one’s close kin is a source of variation in socio-political attitudes, especially those concerning sex roles. Drawing on the evolutionary theory of inclusive fitness gained through relatives, it suggests that individuals with greater expected future fitness returns from females will hold more liberal attitudes than those expecting greater future fitness returns from males.
Methods
We examine the effects of various GFI metrics on 11 sex role attitudes across respondents from 42 countries. GFI metrics were the number of kin of each sex, with these same effects discounted by relatedness, residual reproductive value, and both relatedness and residual reproductive value combined. We also examine differences in attitude prediction when examining effects among descendant-only versus all kin, and accounting for emotional closeness and proximity between kin.
Results
Accounting for relatedness and residual reproductive value improved attitude prediction more so than just number of kin. In direct contrast to previous work, individuals with female-biased future fitness interests demonstrated more conservative sex role attitudes. Attitudes did not correlate with an individual’s relative balance of fitness interests from males versus females. Effects were stronger when limiting kin to descendants only (but still not supportive of GFI Theory). Discounting by emotional closeness and proximity did not substantially alter the results, and there was little evidence of effect variation among world regions.
Conclusion
Overall, GFI Theory did not receive convincing support from our findings. We recommend more extensive modelling and empirical testing of GFI theory in order to understand the disparities in support for GFI between studies.
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Data Availability
The datasets generated and analysed in the current study are available on the Open Science Framework (https://osf.io/fj4br).
References
Allen, B., Nowak, M. A., & Wilson, E. O. (2013). Limitations of inclusive fitness. Proceedings of the National Academy of Sciences of the United States of America, 110(50), 20135–20139.
Betzig, L., & Lombardo, L. H. (1992). Who’s pro-choice and why. Ethology and Sociobiology, 13(1), 49–71.
Blake, K., Fourati, M., & Brooks, R. (2018). Who suppresses female sexuality? An examination of support for islamic veiling in a secular muslim democracy as a function of sex and offspring sex. Evolution and Human Behavior, 39, 632–638.
Blake, K. R., Anjum, G., & Brooks, R. C. (2021). Family and gendered fitness interests effects on attitudes toward women’s veiling, status-seeking and stereotyping of women in Pakistan. Adaptive Human Behavior and Physiology, 7(4), 382–402.
Brooks, R. C., & Blake, K. R. (2021). Gendered fitness interests: a method partitioning the effects of family composition on socio-political attitudes and behaviors. Evolution and Human Behavior, 42(4), 295–303.
Burnstein, E., Crandall, C., & Kitayama, S. (1994). Some neo-darwinian decision rules for altruism: weighing cues for inclusive fitness as a function of the biological importance of the decision. Journal of Personality and Social Psychology, 67, 773–789.
Glick, P., & Fiske, S. (1996). The ambivalent sexism inventory: differentiating hostile and benevolent sexism. Journal of Personality and Social Psychology, 70, 491–512.
Hamilton, W. D. (1964). The genetical evolution of social behaviour. I. Journal of Theoretical Biology, 7, 1–16.
Kaplan, H., Gurven, M., Hill, K., & Hurtado, A. (2005). The natural history of human food sharing and cooperation: A review and a new multi-individual approach to the negotiation of norms. In Gintis, H., Bowles, S., Boyd, R., & Fehr, E. (Eds.), Moral Sentiments and Material Interests: On the Foundations of Cooperation in Economic Life (pp. 75–113).
Kerry, N., Blake, K. R., Murray, D. R., & Brooks, R. C. (2021). Male descendant kin promote conservative views on gender issues and conformity to traditional norms. Evolutionary Human Sciences, 3, e34.
Kerry, N., & Murray, D. R. (2018). Conservative parenting: investigating the relationships between parenthood, moral judgment, and social conservatism. Personality and Individual Differences, 134, 88–96.
Kerry, N., & Murray, D. R. (2019). Politics and parental care: experimental and mediational tests of the causal link between parenting motivation and social conservatism. Social Psychological and Personality Science, 11(2), 284–292.
Luberti, F. R., Blake, K. R., & Brooks, R. C. (2020). The Effects of the mating market, sex, Age, and income on Sociopolitical Orientation: insights from evolutionary theory and sexual Economics Theory. Human Nature (Hawthorne N Y), 31(1), 88–111.
Lundberg, S. (2005). Sons, daughters, and parental behaviour. Oxford Review of Economic Policy, 21(3), 340–356.
Muthukrishna, M., Bell, A. V., Henrich, J., Curtin, C. M., Gedranovich, A., McInerney, J., & Thue, B. (2020). Beyond Western, Educated, Industrial, Rich, and democratic (WEIRD) psychology: Measuring and mapping scales of cultural and psychological distance. Psychological Science, 31(6), 678–701.
Nowak, M. A., Tarnita, C. E., & Wilson, E. O. (2010). The evolution of eusociality. Nature, 466(7310), 1057–1062.
Oswald, A. J., & Powdthavee, N. (2010). Daughters and left-wing voting. Review of Economics and Statistics, 92(2), 213–227.
Price, M. E., Pound, N., & Scott, I. M. (2014). Female economic dependence and the morality of promiscuity. Archives of Sexual Behavior, 43(7), 1289–1301.
Prokos, A. H., Baird, C. L., & Keene, J. R. (2010). Attitudes about affirmative action for women: the role of children in shaping parents’ interests. Sex Roles, 62(5–6), 347–360.
Stewart-Williams, S. (2007). Altruism among kin vs. nonkin: effects of cost of help and reciprocal exchange. Evolution and Human Behavior, 28(3), 193–198.
Warner, R. L. (1991). Does the sex of your children matter? Support for feminism among women and men in the United States and Canada. Journal of Marriage and the Family, 53(4), 1051–1057.
Warner, R. L., & Steel, B. (1999). Child rearing as a mechanism for social change: the relationship of child gender to parents’ commitment to gender equity. Gender & Society, 13, 503–517.
Washington, E. (2008). Female socialization: how daughters affect their Legislator fathers’ Voting on Women’s Issues. The American Economic Review, 98(1), 311–332.
Acknowledgements
This manuscript was supported by a Discovery Project grant from the Australian Research Council to the last author [DP160100459] and a Discovery Early Career Researcher Award to the first author [DE210100800]. We thank Melody Ooi, Sarah Zhang, Freya Satarwala, Meg McCartney, Lindsie Arthur and Tessa Cowley for support with data collection.
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Blake, K.R., Wu, A., McGovern, H. et al. Number of Close Kin but Not Gendered Fitness Interests Shapes Sex Role Attitudes. Adaptive Human Behavior and Physiology 9, 37–53 (2023). https://doi.org/10.1007/s40750-022-00207-6
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DOI: https://doi.org/10.1007/s40750-022-00207-6