Fathers' eye colour sways daughters' choice of both long- and short-term partners.

In several species, mate choice is influenced by parental features through sexual imprinting, but in humans evidence is scarce and open to alternative explanations. We examined whether daughters' preference for mates with light vs dark eyes is affected by the eye colour of parents. In an online study, over one thousand women rated the attractiveness of men as potential partners for either a long- or a short-term relationship. Each male face was shown twice, with light (blue or green) and with dark (brown or dark brown) eyes. Having a light-eyed father increased the preference for light-eyed men in both relationship contexts. Having light eyes increased this preference too, but only when men were regarded as potential long-term companions. Asymmetrically, in real life, father's eye colour was the only predictor of partner's eye colour; own colour was irrelevant. Mother's eye colour never mattered, affecting neither preferences nor real-life choices. The effect of paternal eye colour was modulated by the quality of the relationship between father and daughter, suggesting (flexible) sexual imprinting rather than a simple inheritance of maternal preferences. Our data provide evidence that in humans, as in birds and sheep, visual experience of parental features shapes later sexual preferences.