It’s not you, it’s my hormones Testosterone Influences | Lisa Welling | TEDxOaklandUniversity

hello everyone thank you for the wonderful introduction as he said my name is dr. Lisa Welling and today I want to talk to you all a little bit about the science of Attraction we know in animal work for example that many bird species the females attracted to brightly coloured feathers in males presumably because it's signals genetic fitness similarly male chimpanzees are attracted to sexual swellings and female chimpanzees because of signals fertile status but what about humans what makes someone physically attractive now this may sound like a simple question but how would they were able to take a beautiful actress like America Ferrera and turn her into Ugly Betty like our bodies our behavior and our preferences have been shaped by millions of years of evolution albeit not the only important thing in our lives of course physical attractiveness is very important for romantic and sexual relationships which of course impact the course of our lives and the evolution of our species for most you meet someone and you decide whether or not to pursue a relationship based on a mutual attraction so a lot of my research is interested in what causes that initial attraction and why despite the widely held belief that beauty is in the eye of the beholder there's actually a great deal of evidence that there is cross-cultural agreement on what traits are considered attractive healthy-looking people are considered more attractive looking than relatively on healthy-looking people people with symmetrical features are considered more physically attractive than people with relatively asymmetrical features here in these two examples the more attractive individuals the one on the left and we see predictable patterns in what is known as sexually dimorphic features now sexual dimorphism is a fancy way of referring to physical differences between the sexes like feminine traits and women and masculine traits in men within either sex an individual can be more or less steps typical but there is evidence to suggest that feminine women and masculine men possess other characteristics desirable in a potential mate for instance these individuals actually report having fewer health problems and greater longevity than relatively sex atypical counterparts so if you reproduce with these individuals these genes for fighting infection could be directly beneficial to your offspring who receive these genes for genetic immunocompetence and indirectly beneficial to you because your offspring are thus more likely to survive into adulthood reproduce themselves and thus spread your genetic line not only our sex hormones responsible for the development of these secondary sexual characteristics at puberty there's evidence suggests that these hormones continue to influence who we find attractive later on in life now given the evidence I just presented to you may be asking yourself well then why is it we don't always go for hyper feminine and hyper masculine men if they're so good these genetic fitness some benefits that we could actually obtain well for starters they may not be interested in you sorry to break us yeah our ability to attract and retain a potential mate also depends on what science has lovingly referred to as our own market value so basically it also depends on what you can bring to the table there's also evidence that masculine men in particular do possess some traits on average that are not desirable in a potential partner so masculine men are average on average are more dishonest have more one-night stands and lower interests and children so attraction to these characteristics depends largely on how people resolve these cost-benefit trade-offs one way which it seems they resolve this is through their hormone levels hormones are chemical messengers that are released into the blood or tissue fluid system that traveled to target cells some distance from the source behavioral endocrinology is a study of the relationship between hormones and behavior these relationships can be bi-directional which means that hormones can influence behavior and behavior can also influence hormones three main classes of sex steroid hormones have received the most attention when it comes to human attractiveness research progestin see the key hormone being progesterone are mainly involved in pregnancy estrogens the key hormone being Astra dial are largely responsible for the development of female secondary sexual characteristics and androgens the key hormone being testosterone are largely responsible for the development of male secondary sexual characteristics regardless of their perceived primary function all three of these classes of hormones are present in both men and women for instance in your average 28-day woman's menstrual cycle menstruation begins on day one of what is called the follicular phase menstruation continues for about five days and in the follicular phase continues until ovulation which is when an egg is released and conception can occur after ovulation we have what's known as the luteal phase which is when a fertilized embryo can implant into the uterine lining and pregnancy can occur if there is no pregnancy hormone levels drop and the cycle starts over as you can see a sturgeon testosterone and progesterone all very predictably across a woman's menstrual cycle and different points of a menstrual cycle have markedly different hormonal profiles so for instance in the late follicular phase which is when sex can result in conception you can see that estrogen is relatively high testosterone is relatively high but progesterone is very low meanwhile in the middle of the luteal phase when conception isn't going to happen you have reasonably high estrogen but still lower low testosterone and very high progesterone levels now previous researchers have found that women's reported attraction to masculine characteristics in men are actually higher when a woman is near ovulation so in other woods where it's women increase their attraction to these signs to genetic fitness when they're most likely to conceive it seems likely that hormones are driving these effects but which hormones and how do we actually measure differences in phase preferences we spend a lot of time looking at phases and they are crucial for person perception they convey relevant information like age sex and emotion and there's even evidence to suggest that the face is the most important element in determining someone's overall physical attractiveness now you may ask yourself why does that matter well although both men and women report that physical attractiveness is not an important determinant when it comes to choosing who to date evidence suggests there by and large kidding themselves for example the single biggest predictor of satisfaction with a blind date is perceived physical attractiveness of the other person on top of that people prefer to associate with date reproduce with and they even prefer to employ and vote for physically attractive people there's evidence that physical attractiveness even influences fundamental aspects of human care mothers report bonding more closely with cuter infants children who are cute are less likely to be punished when they misbehave I've got two adorable nephews that can attest to that and one study even found that nurses provide a higher quality of care to cuter premature born newborns versus relatively less cute premature newborns but before you go losing all faith in humanity because we are the shallowest race in existence let me just stress that these are not necessarily conscious choices that people aren't purposely choosing to invest necessarily in attractive people but there is something about physical attractiveness that grabs and holds our attention and the Elvis research suggests that studying the determinants of physical attractiveness can really provide important insights into human social interactions so to actually measure these differences in preferences we'd like to use phases since they're so important in physical attractiveness perceptions and we use sophisticated computer graphics software this software can objectively and mathematically measure differences in face shape between types of faces and then apply those differences to other faces we can make them older younger change their ethnicity or sex or change other aspects of face shape like sex typicality so first we start by making average or prototype faces and we do this by mapping out identical points on series of faces and then our software can average a chunk of faces together so on the Left we have a female prototype face and on the right we have a male prototype face each of these faces are actually made up of 60 separate identities then our software can measure the vector differences between the points on one prototype face and the same points on the other prototype face to reveal the vector differences or average differences between your average man and your average woman by applying these differences to other identities we can objectively make more or less sex typical versions or in other words we can make feminized and masculine eyes versions of other individuals so in the center here you have original me on the left you've got feminized me and then on the right you've got masculinized me I've never looked so good now the important thing to take from this is that although two-dimensional sex typicality has changed other aspects of face shape have remained the same so background is identical skin texture remains unchanged and anyone who knows me could tell from any of these examples that that's me so identity remains the same now if we bring women into the lab and test them at different points in their menstrual cycle we ask them to choose between a series of phases which of these two phases do you think is the most attractive we find the predictive pattern that women are more attracted to masculine faces near ovulation so women are more likely to choose the guy on the right near ovulation now this time we actually measured their hormone levels to see which hormones seem to be driving this effect remember around ovulation we've got high testosterone level high estrogen and low progesterone so with some fancy math we were able to look at the independent contributions of each of those hormones and what we found was that testosterone seemed to be driving the effect in other words women's preferences for masculine men are higher when their testosterone is high near ovulation then when the same woman's testosterone is relatively low so here the higher bars indicate a greater preference for masculine men there's other evidence in favor of this hypothesis so for example a woman's preference for masculine men increases when her sex drive goes up and women's sex drive has been linked quite freely with testosterone level otherwise you see similar patterns of diurnal variation in both masculinity preferences in women and testosterone level so basically testosterone is highest in the morning and decreases throughout the day women's preferences for masculine men are also higher in the morning and lower in this in the evening the same women so all of this suggests that testosterone influences women's preference for rugged manly men but when most people think of testosterone they think of men so this begs the question does testosterone also contribute to variation and face preferences among men now in men testosterone has been linked to several different constructs it's linked to aggression vocational choice mating strategy and even reproductive success if we run men through a very similar task of choosing between different faces we find a similar pattern for testosterone being related to preference for sex typicality so here the feminine face is the one on the left basically we've shown this in two studies now the one on the left was looking at natural variation in testosterone suggest men's natural levels when it was high relative to when it was low and the study on the right actually looked at manipulating testosterone pharmacologically so participants came in twice once we gave them testosterone a synthetic testosterone and a second time we gave them placebo in both of these studies what we found was out over all men's preferences for feminine women were higher when their testosterone levels were high relative to when the same men's testosterone levels were low similarly both women men's rather preferences for feminine women and their testosterone decrease with age and also you see predictable patterns when you look at winning or losing a competitive task when men win a competitive task their testosterone just kind of goes through the roof it goes up big-time but if they lose a competitive task it just plunges through the floor so what you see we brought men into the lab this has actually been shown in multiple contexts we've shown it with you know actually playing a sport and all the way to flipping a coin and betting on heads or tails you win your testosterone goes up yay if it you lose it goes down unfortunately now if we brought that when we brought them into the lab we had them play a video game task against an unseen male opponent and unbeknownst to our participants we actually fixed the outcome so they are randomly allocated to win or lose this video game task and what we found was that when men won the video game tasks their preference for feminine women were higher than when men lost so this tracks the testosterone pattern all of this goes to suggest that testosterone increases preferences for sex typical opposite sex faces in both men and women so the translation here is that hormones influence your romantic partner preferences this is just one example of one hormones influence on one aspect of human behavior but there are many others some of them are relatively subtle like the examples I discussed today others are more obvious but they're all nonetheless fascinating just imagine you're out in the town with friends and someone catches your eye at the bar maybe things go well so you decide to start dating maybe things go really well and so you get married and then maybe you decide to start a family of your own this story or some variation of the story is actually very common you can get your happily ever after or at least some version of a never after and it could all start with the right hormonal profile or maybe the hormones just weren't in your favor thank you dr. lisa welling everyone

Channel: TEDx Talks

Views: 686,064

Keywords: TEDxTalks, English, United States, Social Science, Biology, Evolution, Psychology, Relationships, Sex

Id: -LZZJTR0GxE

Length: 16min 25sec (985 seconds)

Published: Mon Nov 23 2015