Men find firm breasts most attractive — but have differing opinions of how big they should be, according to research published in Evolution & Human Behavior.

The study of 267 men found medium size breasts were judged as being the most attractive overall in Brazil, Czech Republic and Namibia. Large breasts were judged as being the most attractive in Cameroon. But there was considerable variation in breast size preferences between individuals.

There was less variation when it came to shape. Cross-culturally, the researchers found a systematic preferences for a firm breast shape when compared with more drooping shapes.

PsyPost interviewed the study’s corresponding author, Jan Havlíček of Charles University in Prague. Read his responses below:

PsyPost: Why were you interested in this topic?

Havlíček: Human female breasts are unique among primates as they develop during puberty and are permanently enlarged throughout the adulthood. In contrast, females of non-human primates develop their breast only during pregnancy and breastfeeding. One of the hypothesis targeting this issue suggests that firmness of women’s breast may indicate residual fertility. Based on this men are expected to prefer firm breasts. Virtually all previous studies focused on breasts size and none of them tested for breast shape preferences.

What should the average person take away from your study?

We found cross-culturally consistent preference for firm breasts which are typical for women in young adulthood. In contrast, we found a quite large variation in breast size preferences. In most tested countries the medium size breasts were the most preferred.

Are there any major caveats? What questions still need to be addressed?

Yes, future studies should test for interaction between shape (firmness) and size. It is possible that large breasts are preferred in younger women and smaller breasts in relatively older women as they might give younger appearance. Further, it is currently not clear what factors affect variation in preferences for breast size. One may, for instance, speculate whether men’s preferences are not influenced by breast size of their mothers.

The study was titled: “Men’s preferences for women’s breast size and shape in four cultures.”