New research challenges idea that female breasts are sexualized due to modesty norms

A new study published in the Archives of Sexual Behavior suggests that heterosexual men’s sexual attraction to female breasts may be rooted in evolved biological mechanisms rather than shaped by cultural rules. The findings come from an indigenous population in Papua, Indonesia, where researchers found no significant difference in men’s reported sexual interest in breasts—despite whether they grew up in a time when toplessness among women was common or in a more recent period when women typically wore tops in public.

The study was designed to explore a long-standing debate: are men sexually attracted to female breasts because of cultural taboos that make them alluring by being hidden, or is there a more universal, perhaps evolutionary reason behind the fascination? In many modern societies, the sexualization of female breasts is often explained as a product of modesty norms and media portrayals.

But some researchers have proposed that male interest in breasts could stem from biological cues, such as signals of fertility or health. To test these competing ideas, the researchers focused on a population relatively untouched by Western media influence but experiencing a recent shift in clothing customs.

“We are a team of scientists led by Professor Piotr Sorokowski who are interested in cross-cultural studies and comparisons of different societies, for the sake of trying to answer the question ‘nature or nurture?'” explained study author Michał Stefańczyk, an assistant professor at University of Wroclaw and University College of Professional Education. “Since we have evolutionary backgrounds, our studies often orbit around sex-related subjects. And – whether due to our nature or the Western nurture (although our findings suggest the former) – it was not far from sex-related subjects to come up with the breasts study.”

The study was conducted among the Dani people, an indigenous group living in the Central Highlands of Papua. The Dani had historically practiced public toplessness among women, but over the past four decades, a cultural shift has taken place. Today, most Dani women wear clothing that covers their breasts, influenced by broader social changes. This shift provided a rare opportunity to compare two generational groups—one raised when toplessness was still the norm, and another raised when breast covering had become more widespread.

The researchers recruited 80 Dani men, divided evenly between two age groups. The younger group ranged from 17 to 32 years old, and grew up after toplessness had largely disappeared. The older group ranged from 40 to 70 years old, and spent their youth in a cultural context where it was common for women to appear topless in public. The aim was to see whether exposure to public toplessness during formative years influenced how sexually arousing men found female breasts, how often they touched their partners’ breasts during sex, and how important breasts were in shaping their perception of a woman’s attractiveness.

To collect data, the researchers used oral interviews conducted with the help of a local interpreter. Each participant was asked about their memories of women’s clothing norms during their youth, followed by questions about sexual behaviors and preferences related to breasts. These included whether they touched their partner’s breasts during sex, how sexually aroused they felt when seeing a woman’s bare breasts, and how important breasts were in shaping their initial attraction to their partner.

The results showed no significant differences between the two age groups. Both younger and older men reported similar levels of sexual arousal when seeing female breasts, similar frequency of breast-touching during sex, and similar views on how important breasts were for their partner’s attractiveness. Statistical analyses also found no meaningful relationship between age and these measures, suggesting that exposure to toplessness during youth did not shape men’s sexual interest in breasts.

These findings challenge the idea that breasts become sexually attractive only when they are hidden by clothing or subject to social taboo. If that were true, men who grew up seeing female breasts exposed daily in non-sexual contexts would be expected to find them less arousing. But the study found otherwise, supporting the view that male sexual interest in breasts may be more deeply ingrained, possibly tied to biological cues like youth, fertility, or health.

“Female breasts seem to be sexy for men irrespective of them (the breasts) being covered or exposed on a daily basis in public,” Stefańczyk told PsyPost. “Although I want to stress this finding is not final (see limitation section), surely the Western culture, however we perceive it or how we judge it, is not to blame for our Papuan results.”

The authors suggest that breasts may trigger sexual interest because of their shape, symmetry, and development, which could signal reproductive maturity. Previous research has linked larger breasts with higher levels of estradiol, a hormone related to fertility, and with greater body fat, which can also signal nutritional status. The shape and firmness of breasts may also communicate youth, since sagging tends to increase with age. Such cues might explain why men across diverse cultures find certain breast features attractive, regardless of whether those features are typically visible in public.

At the same time, the study does not rule out the influence of culture entirely. While this research provides evidence for an innate component of male interest in breasts, it is still possible that cultural norms can intensify or shape how that interest is expressed. In societies where nudity is rare or taboo, breasts might become more erotically charged. But this would be an amplification of an existing tendency, not the creation of it, the authors argue.

But as with all research, the study has limitations. One important concern is recall bias. The older men were asked to reflect on their experiences and feelings from earlier in life, which may have been influenced by their current environment, where toplessness is no longer the norm. This could blur any differences that once existed between the two groups. Additionally, while the Dani are a non-Western population, they are still only one group. Broader conclusions about human nature would require similar studies in other societies, especially ones where toplessness is still common today.

Another issue is the reliance on self-reported data, which can be influenced by social desirability or misunderstanding. Although the researchers used an interpreter and asked simple questions, cultural differences in discussing sex could have shaped how participants responded.

“There might have been a recollection bias,” Stefańczyk noted. “We relied on what older men remembered feeling when they were younger and saw female breasts, and years of seeing breasts covered (i.e., the recent years) might have influenced their memory.”

“We should go somewhere (we thought of south Africa or northern South America) where different societies live next to each other, but have relatively little contact with each other, and where one of these societies has norms that prohibit women to show their breasts in public, while in the second society women do expose their breasts publicly and it is not a big deal. That would give us sort of a final resolution. If someone wants to fund the following research, they know how to reach me!”

The study also focused solely on male participants, leaving open questions about how women perceive breasts in themselves and others, and whether similar biological or cultural factors play a role in shaping female attitudes.

Despite these limitations, the study provides an important perspective on human sexual behavior by moving beyond assumptions based solely on Western norms. It adds to the growing body of evidence suggesting that some aspects of sexual attraction may be deeply rooted in biology, even as they are influenced by cultural context.

The study, “Nudity Norms and Breast Arousal: A Cross‑Generational Study in Papua,” was authored by Michal Mikolaj Stefańczyk, Piotr Sorokowski, S. Craig Roberts, and Agnieszka Żelaźniewicz.