View Full Version : What are the genetics of breast size?

10-02-2019, 01:16 PM
Women vary a lot when it comes to breast size and shape, even within the same family. Big, medium and small-breasted women exist in all societies, so it makes sense to think that men have different tastes. Do you know if breast size correlates with any other body trait (like % of body fat, BMI, height, skin color, butt size...) or is it completely independent of them? I think it makes sense to assume that overweight women have on average bigger breasts than thin women, but the correlation is far from perfect. Do you know if both mother and father genes are equally relevant when it comes to breast size?

Besides, I've also noticed that some or even most men have breasts, especially if they're above 40. Before you say it, not all of them are overweight. I met a thin man aged +45 that had breasts (he wasn't a transgender either).

10-02-2019, 06:45 PM
Curious topic. Here’s a review article of one signaling pathway impacting mammary gland size

10-02-2019, 06:58 PM
Also https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3483246/

10-03-2019, 11:38 AM
Men's preferences for women's breast size and shape in four cultures


The morphology of human female breasts typical for their permanent fat deposits appears to be unique among primates. It has been previously suggested that female breast morphology arose as a result of sexual selection. This is supported by evidence showing that women with larger breasts tend to have higher estrogen levels; breast size may therefore serve as an indicator of potential fertility. However, breasts become less firm with age and parity, and breast shape could thus also serve as a marker of residual fertility. Therefore, cross-culturally, males are hypothesized to prefer breast morphology that indicates both high potential and residual fertility. To test this, we performed a survey on men's preferences for breast morphology in four different cultures (Brazil, Cameroon, the Czech Republic, Namibia). As stimuli, we used two sets of images varying in breast size (marker of potential fertility) and level of breast firmness (marker of residual fertility). Individual preferences for breast size were variable, but the majority of raters preferred medium sized, followed by large sized breasts. In contrast, we found systematic directional preferences for firm breasts across all four samples. This pattern supports the idea that breast morphology may serve as a residual fertility indicator, but offers more limited support for the potential fertility indicator hypothesis. Future studies should focus on a potential interaction between the two parameters, breast size and firmness, which, taken together, may help to explain the relatively large variation in women's breast sizes.

https://www.researchgate.net/publication/309299836_Men's_preferences_for_women's_breast_siz e_and_shape_in_four_cultures

Resource Security Impacts Men’s Female Breast Size Preferences


It has been suggested human female breast size may act as signal of fat reserves, which in turn indicates access to resources. Based on this perspective, two studies were conducted to test the hypothesis that men experiencing relative resource insecurity should perceive larger breast size as more physically attractive than men experiencing resource security. In Study 1, 266 men from three sites in Malaysia varying in relative socioeconomic status (high to low) rated a series of animated figures varying in breast size for physical attractiveness. Results showed that men from the low socioeconomic context rated larger breasts as more attractive than did men from the medium socioeconomic context, who in turn perceived larger breasts as attractive than men from a high socioeconomic context. Study 2 compared the breast size judgements of 66 hungry versus 58 satiated men within the same environmental context in Britain. Results showed that hungry men rated larger breasts as significantly more attractive than satiated men. Taken together, these studies provide evidence that resource security impacts upon men’s attractiveness ratings based on women’s breast size.