The bikini brain scan, and whether porn makes people see others as bodies

The bikini study

In February 2009 a National Geographic headline read "Bikinis make men see women as objects, scans confirm"². It reported a talk by Susan Fiske of Princeton on brain scans of 21 heterosexual men, and said a region of the brain tied to tool use lit up when they saw scantily clad women². The full paper, with Mina Cikara as first author, came out in print in 2011¹. It says something narrower. The headline put on men as a sex what the data put on some men.

The paper has two parts. In the first, 20 women and 27 men recruited online sorted pictures of women in bikinis or in clothes, mixed with action verbs like push and grab filed under "I" or "she"¹. Pairing bikini pictures faster with "I" verbs would suggest the woman is something acted on, not someone who acts. Neither the women nor the men as a group showed a significant difference¹. It showed up only as a correlation in the men. The higher a man scored on what the researchers of western-thought labelled "hostile sexism", a scale of the belief that women seek to control men and use sex or feminism to gain status, the faster he paired bikinis with "I"¹. That link was borderline, at p = .05¹.

In the second part, 21 heterosexual male undergraduates lay in a scanner while pictures of women and men, sexualized or fully clothed, flashed up for a fifth of a second each¹. The pictures were the kind found in advertisements and on billboards, not porn¹. In men with higher hostile sexism scores, areas used for thinking about other minds were less active when a sexualized woman appeared¹. Men who scored near the bottom of the 6-point scale showed activity there, and men around 4 showed none above baseline¹. When the same men saw a sexualized man, the link reversed, and higher sexism scores went with more activity¹.

No woman was scanned. The first part only ever showed pictures of women, so nobody tested whether women see sexualized men this way¹. The authors write that they do not think the effect is unique to men, since women may see men as useful too, and they left that for a later study¹.

Two more results sit behind the headline. Afterwards the men as a group recognised the bodies of sexualized women better than other bodies, though not their faces, and that had nothing to do with their sexism scores¹. And across all the men, the sexualized female pictures raised activity in a list of areas that included premotor cortex¹. The paper does not call it a tool area. The tool line came from the talk². What the paper measured was a fifth of a second, in 48 men across both parts, with no porn and no second visit to see whether anything lasted¹.

Porn use, a year later

So the scan cannot say whether porn makes anyone see others as objects, or whether that lasts. The study that comes closest followed Dutch teenagers. Peter and Valkenburg surveyed 2,341 adolescents aged 13 to 20 in mid 2006, again six months later, and again in mid 2007³. The 962 who answered all three times and had seen explicit material went into the analysis³.

Each time they said how often they had looked at explicit pictures or films on purpose, and how far they agreed with five statements³. One was "There is nothing wrong with boys being primarily interested in a woman's body"³. Girls and boys answered the same five, and all five are about women, so the study measured how both sexes see women and never how either sees men³. That is a belief put into words, a long way from a brain scan.

In girls and boys alike, more use at the start predicted stronger agreement a year later, even after taking account of what each teenager believed at the start, and the push did not differ between girls and boys³. It ran the other way too. Stronger agreement at the start predicted more use a year later, though only in boys³.

The standardised effects were 0.15 from use to belief and 0.09 from belief to use³. Liking sat in the middle. More use led to liking the material more, liking predicted the beliefs, and once liking was in the model the direct path from use was no longer significant³. The authors leave two futures open. The loop could spiral upward, or fade as teenagers grow up, get used to the material and take on roles where treating women as objects is not tolerated³. Only longer studies can tell which, they say³.

Adults, in four countries

Studies of adults find the same link, though as snapshots taken once. Some asked only men. Wright and Tokunaga surveyed 187 men from undergraduate courses at a large US public university, all attracted to women, average age 21⁴. The more porn they watched, the more they agreed with lines like "an attractive woman asks for sexual advances", and that view went with more acceptance of violence against women⁴. Reading men's magazines such as Maxim and watching reality shows such as Jersey Shore went with the same view, each counted on its own⁴. The authors say the arrow could also run backwards, with men who already hold these views picking media that agree with them⁴.

Willis, Bridges and Sun asked in both directions. They surveyed 2,815 heterosexual women and men in Germany, Korea, Taiwan and the US, most of them students, on how often they used porn and how far they agreed with four statements, each written about the opposite sex⁵. The version women answered included "When I pass by an attractive man, I tend to check out his butt"⁵. In every country, more porn use went with more of these habits, at correlations from 0.29 to 0.37⁵. In three of the four countries that link did not differ between women and men, and in Korea it was stronger in men⁵. Men reported more of the habits than women in all four, and they also used porn more often⁵.

One study points the other way. Kohut, Baer and Watts used the General Social Survey, a national US survey of randomly chosen adults, with answers from 14,101 women and 10,946 men between 1975 and 2010⁶. The porn question it used asked whether people had watched an X-rated film in the past year⁶. Women and men who had were more supportive than those who had not of women working outside the home, of women in positions of power and of legal abortion⁶. On women in power the gap was larger among women than among men⁶. Two questions showed no difference. Users were no more and no less likely to call themselves feminists, and when asked who gains and who is hurt when the man supports the family and the woman cares for the home and children, they answered the same as nonusers⁶. Each of those two was asked in a single year, 1996, of 923 and 630 people, and the authors say both tests may have been too small to find a difference⁶. They call all their effects small, say they may mean little in daily life, and think some third factor more likely explains them than porn itself⁶. The survey also asks about something else. Views on women at work and in office are one question, and how a person looks at a stranger is another, and the same person can score well on the first and badly on the second.

Hooked, or only heavy

None of those studies asked about addiction. They measured how often people watched. A Czech team asked whether feeling hooked adds anything⁷. In 2017 they surveyed people mostly recruited through the country's largest erotic website and kept 1,272 heterosexual men, average age 33⁷. A 12-question scale measured signs of addiction, like staying longer than planned and failing to cut down⁷. Five questions asked how often each man looked at people as bodies, from scanning someone's figure to undressing passers-by with his eyes⁷. None of the five said whether the person looked at was a woman or a man⁷.

Men with more signs of addiction looked at others this way more often⁷. Adding how often they watched porn left that link almost unchanged⁷. How often they watched mattered too, with a medium-sized link of its own, but feeling hooked carried something that frequency did not⁷. The authors warn that both measures involve watching, so the addiction link cannot be cut loose from porn itself⁷. It was one survey at one moment, and most of the men reported few signs of addiction⁷. It asked no women, and the authors list that as the next question⁷.

And after quitting

Does any of this fade when someone stops? We found no study that measured how people look at others before and after they quit porn. The longest data is the Dutch panel's single year, and its authors list growing up and getting used to the material as things that could shrink the effect, without testing them³.

The Czech team did test one worry that quitters raise. Their gaze questions came from interviews with men seeking treatment⁷. Citing that interview study, the authors describe addicted men who, with porn out of reach, walked near a nudist beach or leered at women from a balcony⁷. If quitting only moved the looking onto the street, that kind of behaviour should sit between addiction and looking at people as bodies. In a second analysis of the same 1,272 men, it did not⁸. Three links tied the addiction questions to the gaze questions directly, and all three were weak⁸. The strongest, a partial correlation of 0.12, joined undressing passers-by with the eyes to thinking about porn sites while offline⁸. The other two, at 0.07 each, joined staring at body parts to staying on porn sites longer than planned or wanting a few more minutes⁸. The authors call the uncertainty around all three broad, and few men in the sample reported signs of addiction, which they say likely weakened every link⁸.

So, does porn make people see others as bodies, and does it last? The bikini headline joined two halves that no study has joined. The scan was a fifth of a second in 21 men, and the effect needed both a sexualized picture and a man with higher hostile sexism scores¹. The surveys are where porn comes in. In four countries the correlations sat around 0.3⁵. In the Dutch panel the effects a year apart were 0.15 and 0.09 once starting levels were counted, and the reverse direction held only in boys³. Most of this research asks only how men look at women. In the one study that asked women how they look at men, the link with porn use came out much the same in women as in men⁵. Whether it lasts after someone quits has not been studied. The only clue so far is weak. In one Czech survey, what men did when porn was out of reach did not sit between feeling hooked and the looking, and the links that did show up were small⁸.

How they found it

• The bikini study had two parts. Online, 20 women and 27 men sorted pictures of women in bikinis or in clothes together with action verbs filed under "I" or "she". In a scanner, 21 heterosexual male undergraduates saw pictures of women and men, sexualized or fully clothed, for 200 milliseconds each, then took surprise memory tests and a sexism questionnaire.
• The Dutch panel surveyed adolescents online three times, six months apart, from May 2006 to June 2007. It asked how often in the past six months they had looked at explicit pictures or films on purpose, and how far they agreed with five statements about women as sex objects. The 90 who had never seen explicit material were left out.
• The four-country study asked one question about how often people used porn to masturbate, and four about looking at the opposite sex as bodies. Each sex answered the version written about the other.
• The Czech survey ran from April to November 2017, mostly through the country's largest erotic website. Addiction was measured with a 12-item scale adapted for online sex, and looking at people as bodies with 5 questions built from interviews with men seeking treatment.
• We searched PubMed for studies that measured objectification before and after people stopped using porn, and found none.

What it cannot tell you

• The bikini scan had 21 men and reported sexism links for 19. With that few, the true size of each link could be much smaller than the number on the chart.
• The bikini scan, the US college survey and both Czech papers asked only men. The Dutch panel asked girls and boys only about women. Only the four-country study asked women how they look at men.
• The scan used pictures of the kind found in advertising, shown for a fifth of a second. Nobody in it was asked about porn, and nobody was scanned twice.
• Only the Dutch panel followed the same people over time, and only for a year. The others are snapshots, which cannot show whether porn use comes first or whether people who already see others as bodies seek it out.
• Most samples were students or visitors to an erotic website who chose to answer. Across its three waves the Dutch panel had a cooperation rate of 54%.
• The questions on looking at people as bodies in the four-country and Czech studies were written by the researchers and have not been fully validated.

In P-Minus

Lowering the gaze, ghadd al-basar, starts at step one in P-Minus. The home screen holds two numbers you set yourself, the times today you saw someone of the opposite sex and lowered your gaze, and the times you did not. Neither is scored, and a gaze you did not lower is never counted as a lapse. The weeks are drawn on the stats screen.

Sources

1. Cikara M, Eberhardt JL, Fiske ST. From agents to objects: sexist attitudes and neural responses to sexualized targets. J Cogn Neurosci. 2011;23(3):540-51.
2. Dell'Amore C. Bikinis make men see women as objects, scans confirm. National Geographic News. 2009 Feb 16.
3. Peter J, Valkenburg PM. Adolescents' exposure to sexually explicit Internet material and notions of women as sex objects: assessing causality and underlying processes. J Commun. 2009;59:407-33.
4. Wright PJ, Tokunaga RS. Men's objectifying media consumption, objectification of women, and attitudes supportive of violence against women. Arch Sex Behav. 2016;45(4):955-64.
5. Willis M, Bridges AJ, Sun C. Pornography use, gender, and sexual objectification: a multinational study. Sex Cult. 2022;26:1298-313.
6. Kohut T, Baer JL, Watts B. Is pornography really about "making hate to women"? Pornography users hold more gender egalitarian attitudes than nonusers in a representative American sample. J Sex Res. 2016;53(1):1-11.
7. Novakova P, Chvojka E, Ševčíková A, Blinka L, Wright P, Kane S. Men's internet sex addiction predicts sexual objectification of women even after taking pornography consumption frequency into account. Front Psychol. 2025;16:1517317.
8. Nováková P, Chvojka E, Ševčíková A, Blinka L. Withdrawal-motivated behavior does not connect internet sex addiction and sexual objectification, but craving does. Stud Psychol. 2025;67(4):343-56.

Sources checked October 2026.