Is fertility linked to attractiveness

Keep your eyes open when choosing a partner: a strongly masculine face suggests poor sperm quality

Burjassot (Spain) - Does a man's attractive face also signal great fertility and healthy children? That depends, has now shown an international study. Accordingly, men with a distinctly masculine face are less fertile than men with softer facial features. This contradicts a hypothesis that the strength of male secondary sexual characteristics suggests biological fitness. The explanation: On the one hand, men benefited in the course of evolution from masculine characteristics that make them more assertive and help them to achieve a higher rank. On the other hand, the associated high testosterone level has been shown to have a negative effect on sperm production. Interestingly, women only rate men's strongly masculine faces as very attractive if they do not want to form a permanent bond. In this way, they behave biologically sensibly if they prefer men for a long-term relationship who are less dominant but more fertile, reports an international team of biologists in the "Journal of Evolutionary Biology".

"Our results show that the relationship between the attractiveness of a man's face and the quality of his semen may depend on how one defines 'attractiveness'," write Carles Soler of the Universitat de València and his colleagues. If it is only about a short sexual adventure, a masculine face is particularly attractive to women. Then the following applies: the more attractive the man, the worse the quality of his sperm. In contrast, when looking for a permanent partner, men with softer facial features do better and the following applies: the more attractive, the more fertile.

The study “focused” on 50 men between the ages of 18 and 36 years. The researchers assessed their sperm quality on the basis of mobility, cell shape and concentration of the sperm in the seminal fluid. Just by looking at a portrait photo, 226 young heterosexual women and men from Spain and Colombia rated the attractiveness of the faces on a scale from 0 to 10. The women should think of a partner for a long-term relationship. The men were asked to estimate how attractive women would rate each face when looking for a partner. The biologists used objective measurements to determine how masculine each face was. The width of the face - the distance between the cheekbones - is a decisive feature. It is known that the wider the distance, the more masculine the face and the higher the testosterone level, which in turn is associated with properties such as aggressiveness, dominance and physical strength.

The more masculine the facial features, the worse a man's semen quality was. In contrast, the more attractive a face was rated by the respondents, the better it was. Both women and men of both nationalities were therefore able to draw conclusions about fertility from a man's face. In an earlier study, women assessed the attractiveness of male faces in terms of a short-term relationship - with exactly the opposite result: Strongly masculine traits appeared most attractive and thus the men with the poorest semen quality did the best.

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