Publication Type

PhD Dissertation

Publication Date



Bioecological exchange theory is proposed, which resolves contradictions between sexual strategies theory and social role theory. People are hypothesized to flexibly shift their mate preferences in response to the percentage of resources they can provide within a couple, but not limitlessly. Men are hypothesized to facultatively shift between 25-100% of provisioning and women from 0-75% of provisioning, as seen in foragers. Both sexes are then hypothesized to trade provisioning for a reciprocal amount of childcare in a partner. Study 1 uses a sample of undergraduate Singaporean women (n = 197) to demonstrate that the more women expect to contribute to their household income, the less important social level becomes in a long-term mate. Study 2 uses an international community sample (n = 155) to show that both men and women expect to make less than their spouses when low in income, women expect to make the same as their spouses when high in income, and men expect to make more than their spouses when high in income. Women expect greater equality of provisioning and childcare the more they make, while men expect to make more than their spouses and do less childcare the more they make. Study 3 primed Singaporean undergraduates (n = 546) to feel like they would be high-earners or low earners when they graduate, and tested the effects of these conditions on preference for relative income across five levels of homemaking. It was revealed that women want men who make more than them even when husbands are willing to do 100% of childcare when low in income, but are willing to marry men who make less than them if husbands are willing to do 50% or more of housework and childcare when high in income. Men want potential wives to make more than them when low in income unless their wives do 100% of housework and childcare, but when high in income men find women making less than them to be acceptable across all levels of homemaking, except when women are unwilling to do any. These studies provide initial support for bioecological exchange theory, and highlight the importance of considering relative income within potential couples instead of simply between intrasexual competitors, as well as the underestimated role of parental care on human mate choice.


social exchange, division of labor, mate selection, paternal care, parental investment, sex differences

Degree Awarded

PhD in Psychology


Psychology | Social Psychology


LI, Norman

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Last Page



Singapore Management University

City or Country


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Creative Commons License

Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License
This work is licensed under a Creative Commons Attribution-Noncommercial-No Derivative Works 4.0 License.

Available for download on Friday, May 18, 2018