Cognitive Bias and Mate Choice

Sexual mates resemble each other on physical traits, personality factors and political opinion. We extend this line of research to one of the most prominent cognitive biases, unrealistic optimism—the tendency for individuals to overestimate the chance of favourable outcomes occurring and underestimate the chance of bad. Using data from a national representative sample of the English population over age 50, we find that there is a moderate alignment of mates on cognitive bias, similar in range to broad personality factors. Importantly, we also provide evidence that these similarities are driven by direct selection on bias rather than social homogamy, and initial mate choice rather than transmission mechanisms, such as persuasion and imitation. We discuss the implications of mate selection on cognitive bias in the context of household decision-making, income inequality and intergenerational transmission.