Antibiotic Protects Men from Being Too Trusting of Attractive Women

By Breanna Draxler | April 30, 2013 9:44 am

Women can coerce men by attraction alone. Image courtesy of vgstudio/Shutterstock.

The ruse is common in spy movies—an attractive female saunters in at a critical moment and seduces the otherwise infallible protagonist, duping him into giving up the goods.

It works in Hollywood and it works in real life, too. Men tend to say yes to attractive women without really scrutinizing whether or not they are trustworthy. But scientists have shown, for the first time, that a drug may be able to overcome this “honey trap,” and help men make more rational decisions.

Nearly 100 men participated in the study; half were given minocycline, an antibiotic normally used to treat acne, and half were given a placebo. After four days of this drug regimen, participants played a computerized one-on-one trust game with eight different women, based only on pictures of the female players.

In each round, the male player was given $13 and shown a picture of one of the female players. The male player would choose how much money he wanted to keep and how much he wanted to give to the female player. The amount given away was then tripled, and the female player would decide whether to split the money with the man or keep it all for herself. Unbeknownst to the men, however, the women kept the money every time.

The researchers also asked the men to evaluate the photos of the females to determine how trustworthy and attractive they appeared, on a scale of 0 to 10.

Just as the researchers hypothesized, the men who had taken the placebo were more trusting of attractive women than unattractive ones: these men gave about 65 percent of their money to the women they rated as attractive, but only 50 percent to those they found unattractive. Those men on the antibiotics, though, gave approximately 50 percent to each group of women, regardless of their attractiveness. The results of the study appeared in Nature earlier this month.

Scientists think the drug may clear the brain of distractions like, in this case, arousal, to improve focus for making rational decisions. And these scientists aren’t the first to show that the antibiotic has effects other than getting rid of zits. Other studies have demonstrated that minocycline can improve patients’ focus on social cues, encourage sober decision making and improve the symptoms associated with schizophrenia and depression.

While taking risks in the presence of attractive women might be a good thing when men are looking for mates, that’s not necessarily the case when it comes to social or financial decisions. Just take it from the lineup of subpar movie spies who have gotten duped.

Percentage of money offered by male participants to less- and more-attractive female partners. *** For the placebo group, the offering rate to highly attractive female partners is higher than that to partners with low attractiveness. ### The offering rate to highly attractive partners in the placebo group is higher than that in the minocycline group. Image courtesy of Watabe, et al. 

  • gary bates

    Very nice haha. My mind stops working when I’m around a good looking girl lol.

  • Treason

    How did anyone come up with this premise to test??

  • JonFrum

    And scientists are outraged that Republicans want to cut social science funding.

    • Andrew Kiener

      You read an article suggesting that antibiotics can screw with how the brain processes information, and your response is “waste of money”?

      • scooby509

        I know! It’s as if the guy thinks he’s entitled to vote on how his tax dollars are spent!

      • Bill Adams

        Possibly he read that fewer than a 100 men participated, and knew how worthless such studies always are.

    • Lah99

      If you actually read the article, the implications for understanding schizophrena and depression are the real story here. You can read can’t you..I know critical thinking is out of the question.

      • scooby509

        “Other studies have demonstrated that minocycline can improve patients’ focus on social cues, encourage sober decision making and improve the symptoms associated with schizophrenia and depression.”

        The only connection this study had to schizophrenia or depression was that the drug they studied is being tested as a possible treatment for them. There’s no indication from the text that this study has advanced the understanding of schizophrenia or depression in any way.

        Nice work at “critical thinking” there.

        • Lah99

          I believe you actually made my point. Some see the trees while others see the forest. While this study may not have added anything new, the implications should be obvious to someone not familiar with “other” studies.

          • scooby509

            Spell out these obvious implications, please. We’re all ears.

        • Michael Kennedy

          Minocycline is effective against toxoplasmosis, a parasite that may be related to schizophrenia.

    • Lee Reynolds

      No we don’t. People can spend money on whatever they want.

      Oh, you mean taxpayer funding?

      Taxpayer funding for studies such as this one can come when the federal government balances its books.

  • Brian Allan

    It is true… men do think with a different part of their anatomy when a good looking female is present. Gosh, who would have thought this?

  • Luke Oakridge

    I feel like if this was an article about women being tricked by a man, they’d present the woman as perhaps naive but otherwise just taken advantage of by an sleazy guy. But in this article, the lecture the man about not being rational. It seems like they place more blame on the man being deceived than the woman being deceived.

    • InfinityBall

      Well, you’re going to have to take up your complaint with your imagination.

      • Luke Oakridge

        Can you find any articles in reputable news sources that lecture women on how to be more “rational” when it comes to choosing partners? If not, then why are you complaining about my comment?

  • tomcollins88

    Interesting, but hardly a sound test. Too few men, way too few women, and who was it that judged if the woman was attractive or not? With these variables, the difference between 50% & 65% is extremely small. Also, even if these numbers stay the same with a larger test group, the meaning behind the numbers can mean lot of things. Maybe it increases paranoia, or decreases sex drive, or increases sex drive but towards men.

    • Eric Mastrocola

      “the difference between 50% & 65% is extremely small”
      No- its actually a huge difference statistically.

      • tomcollins88

        Not when your dealing with such a small sampling. All it takes is a few anomalies to radically change those numbers.

        I’ll give you an extreme example. Ask 4 people what their shoe size is, and average it out. If one of them happens to have really big feet, then that can throw the results off by quite a bit. The margin of error is quite high.

        However, if you ask 4,000 people, then your margin of error is much smaller.

        You will never get a “perfect” result without asking 100% of the people, but the more people you ask, the closer you get to your correct result.

        • Nullius in Verba

          A sample of 100 people selected independently of the variable under study give a standard deviation in the percentage of about 5%, so the results ought to be within 10% of the right answer 95% of the time. Two such samples from the same population will be separated by less than 14% about 95% of the time. So the result is probably statistically significant by the usual 95% standard, but only just. Theoretically.

          If you take into account the fact that scientists only report things when they’ve got a 95% result, the significance drops somewhat. So it’s worth taking seriously enough to check into it further, but the experiment needs to be replicated before accepting it.

          • tomcollins88

            That’s IF you were dealing with just one variable and IF the whole population were consistent with the sample. When you start dealing in medicine, then you start talking about a lot of variables. Also, you used the words “selected independently”, where as the article never did. How were these men selected? Do they vary by age & race? What is their medical history? Are any of them related? Just how well was the genetic range of the human population represented in a sampling size of 100? This isn’t your bag of red & blue marbles from your statistics class.

            In further research, I see that the test subjects were only young Chinese men from the same region. Hardly representative of the whole population.

            Also, were any of the men gay? I think that would also distort the results.

            And again, the results, even if they are accurate, can be interpreted many ways, besides the implication that men trust attractive less.

            Now, nowhere did I say that their hypothesis is wrong. But their testing has yet barely scratched the surface. It’s a good first step. But I’m not going to give it any weight personally until more testing with more subjects and with a wider genetic range.

  • Steve Ehrlich

    Sounds like a ruse for grant money.

  • bobby_b

    Developed by ho-hum-looking biologists and chemists and then handed out for free to all better-than-just-ho-hum-looking guys in the area. (“It’s a great new vitamin! Try it!”)

    Takes the good-looking guys out of the local scene, leaving the scientists with a greatly increased chance of scoring with a good-looking woman.

    God, I love the free market!

  • EstoniaKat

    This is nothing that someone who has ever seen a green Orion slave girl didn’t already know.

  • Hapa

    “Unbeknownst to the men, however, the women kept the money every time.”

    Sup with that, ladies?

    • mark enriquez

      surprising? i think not…

  • Bill Cismar

    This whole study is based on a false premise. Or should I say, an unproven premise that I will argue is false because it is so unproven.

    The premise that attractive women are not any more trust worthy than unattractive women is false until proved otherwise.

    It is perfectly rational to argue that evolution has made certain women attractive to men specifically because they are more trustworthy.

    That is an assumption that is just as valid as this experiment premise.

    To make a worthwhile test, It should be repeated where both male and female participants CAN interact in real time and then see which group makes the more accurate assessments.

    Who knows, some of the women that were rated as less attractive might become much more attractive when the can actually move and speak to the males. And maybe males are better at reading someone who is actually animated.

    • InfinityBall

      Rational to argue, but stupid to believe.

      • Chris Mx

        Not sooo stupid. What if attractive females are also more intelligent or more rational? In that case, it might make sense for men to trust them more, even if they are less trustworthy, because they are more able to be trustworthy under certain circumstances. There is a big information problem in this study that economics could tell us about.

  • Rufus

    So the acne medicine worked by not clearing up your face but fixing your head so you didn’t care about women any more. Clever.

  • Michael Kennedy

    Where was this when I was married ? Too late. Oh well.

  • effinayright

    Huh? Antibiotics are drugs that interfere with/destroy bacteria.

    Absent a plausible mechanism, how the EFF could an “antibiotic” change brain function?

    Gimme a frackin’ BREAK!!! Only a complete dumbass would believe crap like this!!!

  • stillComputing

    Just consider the phrase “good looking”. This is someone that makes you feel GOOD simply by LOOKING at them. Not surprising people would extend more trust to such people in the hopes that they might look some more.

  • yvessaintdid

    Or just try to picture them without their makeup on.

    • Don Bartlett

      Exactly, in the morning with their colored contacts out, no makeup, I don’t even remember them from the night before.
      I think it;s the roomate.

  • Sj Rudloff

    Wonder if it works the other way with gals.

  • Danni_l



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