From Academia: Review of the Mate Switching Hypothesis

2017 research published in the journal Personality and Individual Differences explores the reasons why people may leave one relationship to enter another.

‘Mate switching’ can have a number of causes, the authors suggest. Primarily, these include:

(1) Hidden costs associated with a partner which were not apparent on the initial mate selection;

(2) Changes over time in the ‘mate value’ of either partner creating new discrepancies;

(3) The arrival of a new and interested potential partner of “sufficiently incremental value to offset the costs of a breakup”.

The mate switching hypothesis suggests that people have a number of evolved traits associated with the threats and opportunities mate switching presents.

These might include the cultivation or maintenance of ‘back-up partners’, or the ability to watch a current partner’s welfare trade-offs and intuit threats from them.

The mate switching hypothesis sometimes supports the leading ‘good genes’ hypothesis for female infidelity, but sometimes contradicts it.

The ‘good genes’ hypothesis posits that “women have adaptations for securing investment from one man while cuckolding him in order to obtain good genes from an affair partner”.

Mate switching suggests that women may instead be using an increase in mate value accrued during ovulation to attain a higher value partner.

The authors argue the latter better explains some data points around female infidelity, such as the finding that relationship dissatisfaction predicts infidelity in females more so than in males.

Further, 79% of women who have affairs report falling in love with their affair partner, while this is only true of a minority of men. This suggests simply acquiring new genes may not be the best evolutionary explanation for extra-dyadic behaviour in this context.

Find the full study here.