- Sep 4, 2018
Women are attracted to men with healthy faces
Women are attracted to men with healthy faces
Women are subconsciously attracted to men with a high immune system, a new study suggests.
A paper published in Nature Communications today has found a relationship between testosterone, stress hormones, male facial attractiveness and a healthy immune system.
“The more antibodies a man produces in response to a vaccine, the more attractive his face,” said Fhionna Moore, co-author of the study and a psychologist at the University of Abertay Dundee in Scotland.
“We also found that men’s testosterone was related to their immune system and their facial attractiveness: the higher the testosterone, the stronger the immune system and the more attractive the face. Interestingly, this was qualified by levels of stress hormones: the relationships with testosterone were strongest in males experiencing low levels of stress.”
Health, wealth and beauty
A basic notion in evolutionary biology is that there are trade-offs: if an individual is spending more on one thing they will spend less on the other. Testosterone is a costly hormone that is integral for the development of uniquely male traits – some of which are used to entice females of the same species – but it can also suppress the immune system.
There is a limited amount of energy and resources that can be invested in developing male physical attributes and health, so logic states that if an individual invests significantly in external features, he may pay the price in terms of his physical health.
But certain biological attributes or circumstances could allow some males to expend high levels of testosterone whilst maintaining relatively healthy immune functioning. This could mean that a particular male is ‘resource rich’ and can afford excess testosterone without it interfering with an active immune system, which suggests that he can produce healthy offspring – an attractive prospect for females. (literal definition of universal attractiveness in a male)
A healthy hormonal cocktail
Researchers have found, however, that testosterone bears a peculiar relationship to immune functioning throughout the animal kingdom: high or low levels of testosterone are not always correlated with a healthy immune system.
It’s been suggested that the relationship between testosterone and health is influenced by cortisol, a stress hormone. High levels of cortisol are known to suppress the immune system by’blocking’ white blood cells.
So how do cortisol and testosterone interact in sexual signalling, and what respective hormonal levels allow for a strong immune system? In other words, what healthy hormonal ‘cocktail’ is deemed most attractive by females?
Moore and her colleagues administered a hepatitis vaccine to 74 Latvian men in their early twenties. They observed their antibody responses to the vaccine whilst measuring each participant’s levels of testosterone and cortisol. They then asked 94 female students to rank the males’ attractiveness on a 10-point scale.
The team found that men with a strong antibody response to the vaccine – indicating healthy immune function – also had high levels of testosterone, and were perceived as more attractive. Men with low levels of testosterone also tended to have high concentrations of stress hormones, suggesting that their immune responses might have been inhibited by cortisol.
These results suggest that while female face preferences directly correlate with male antibody function, this relationship might be controlled, to some significant extent, by stress hormones.
“The idea is that there are always individuals with good genes who can afford to have high testosterone – to be highly attractive – without paying the cost for this. We need to understand the genetics of this,” commented Dario Maestripieri, a professor of comparative human development at the University of Chicago in the U.S.
“The research makes perfect sense, [and] the question makes perfect sense, so we need similar studies done on different traits. They focused on faces, but you could look at other things. We also need to understand more about the molecular mechanisms through which cortisol and testosterone interact,” he added.
These results were also complicated by other studies, which have suggested that the facial preferences of women might be determined by cultural cues over biological cues.
Moore and her collaborators are now looking at women’s testosterone and cortisol preferences across a number of different countries in addition to social measures of attraction. They are also seeking to identify the specific facial cues of testosterone, stress and health in men.
Composite male faces constructed to differ in levels of testosterone and cortisol. From left to right: low-testosterone, high-cortisol; low-testosterone, low-cortisol.
Credit: Proceedings of the Royal Society B.
Why women prefer "chill" guys - By Charles Q. Choi, Live Science
Women generally find calm, collected men more attractive, and scientists now suggest they know the biology of why that is.
Investigations into what makes men desirable often focus on testosterone. The hormone is linked with masculine facial traits, such as larger jaws and heavier brows, and is typically associated with better long-term health. As such, it might at first glance make sense from an evolutionary point of view if women found testosterone-laden men especially attractive.
However, past studies have often revealed that men with high testosterone levels are not automatically appealing to women, who view such testosterone-laden men as having long-term drawbacks. For instance, the macho guys may lead a "player's" lifestyle, or may also be bad parents.
Instead, human behavioral ecologist Fhionna Moore at the University of Abertay Dundee in Scotland and her colleagues focused on the stress-linked hormone cortisol. Persistently high levels of cortisol can suppress not just the immune system, but also reproductive function. As such, it would make sense if women preferred men with low cortisol levels — that is, those who are not stressed out.
Cool customers win out
First, scientists recruited 39 healthy young male students from the same university and measured their cortisol and testosterone levels from saliva samples they provided. The researchers next had 42 straight female students from a different university rate photos of these men for attractiveness, masculinity and health.
Men with low cortisol levels were often rated as more attractive than guys with high cortisol levels. Testosterone levels were not significantly linked with attractiveness, masculinity or health. <------
For a more complex study, the scientists took the 39 male faces from their initial work and split them into four groups — high-testosterone and high-cortisol; high-testosterone and low-cortisol; low-testosterone and high-cortisol; low-testosterone and low-cortisol. Within each group, all the faces were blended together to help make one composite image. In this way, Moore and her colleagues hoped to see what effects combinations of different hormone levels might have on attractiveness.
The researchers also had 43 heterosexual female university students look at the composite images at times both inside and outside the fertile phases of their menstrual cycles. This enabled the scientists to see what effects female hormones and fertility might have on perceptions of male desirability.
When women were in the fertile phase of their menstrual cycle — that is, when they were more likely to get pregnant — those men with low cortisol levels (so were likely more chill) were seen as more attractive than men with high cortisol levels. Past research suggests that when women are most fertile, they tend to judge men on traits that might best benefit any potential offspring in the long-term, and the scientists noted that a person's general cortisol levels are heritable.
"We speculate, then, that males with low cortisol possess something desirable that women seek to secure for their offspring," Moore said. "This could be, for example, good health or a healthy response to stress."
The results were considerably more complex when women were not in the fertile phase of their menstrual cycle. In those cases, male faces linked either with high levels of both cortisol and testosterone or low levels of both hormones were rated as more attractive than faces associated with high levels of one and low levels of the other.
Prior studies suggest that when women are not in their fertile phase, "we tend to interpret women's preferences as reflecting those for cues to the characteristics that make a man a good long-term partner," Moore told LiveScience.
In this light, men who are healthy or good providers might be important to women not in their fertile phase. "I can speculate that high-testosterone, high-cortisol levels may signal someone who is dominant and may make a good provider — high testosterone is certainly likely to be related to this," Moore said. "Someone with low-testosterone, low-cortisol levels may be someone with good current health."
me rn greenteamaxxing to lower stress