Scientists Find More Evidence Of Sexual Pheromones In Primates

Science has taken a surprisingly long time to uncover the truth about pheromones, in particular the role they play in human and primate mating. Now Japanese scientists may have come close to establishing to everybody’s satisfaction that pheromones do exist in at least primates. If so, it would be harder than ever to claim that they would not also play a part in the mating of our own naked ape species.

As a report in this week’s National Geographic magazine points out, scientists only discovered the first pheromone in 1959 (bombykol, the scent of the female silkworm moth). Despite initial beliefs that pheromones would only exist in insects, scientific researchers have gradually worked their way up the evolutionary ladder to discover similar scent molocules that influence sexual behavior in rodents, pigs, and other mammals. More recently, various research has indicated the presence of pheromones in the ring-tailed lemurs of Madagascar, and this week a Japanese study into the cute little primates added further weight to the theory.

Researchers at the University of Tokyo recently added to that scent profile, finding three additional chemicals called aldehydes, which caused the females to linger longer around the male’s scents.

“We are surprised that the identified odors in this study smell relatively good to humans —fruity and floral,” says study co-author Kazushige Touhara, a biochemist at the University of Tokyo.

To be considered sex pheromones, these odors will have to be shown to affect only lemurs and increase their mating chances, Touhara says. If that is the case, they would be the first sex pheromones ever found in primates.

‘Men Can Smell When A Woman Is Aroused’

According to a recently published paper in the scientific journal – ‘Archives of Sexual Behavior‘ – researchers have found that ‘men process olfactory signals of women’s sexual arousal’. Or to put it in plainer language – men can smell when a woman is turned on.

The research group, from the University of Kent in England, conducted a series of experiments involving young heterosexual men and women in order to determine if a female mating cue – such as sexual arousal – could be transmitted to potential male partners via ‘chemosignals’ (more commonly referred to in this context as pheromones) .

Young heterosexual women with an average age of 19, none of them taking hormonal contraceptives, were shown an erotic (for women) film, and then samples of their sweat were taken using cotton swabs wiped under their armpits when they reported being sexually aroused by the film. Sweat samples were also taken when the young women were not in a state of sexual arousal.

Both types of sweaty scent were then sniffed at by the male volunteers participating in the experiment, all heterosexual men with an average age of 21. It was indeed found that the men rated the scent of the women in a sexually aroused state as being more attractive.

In a further twist to the experiment, the men were then shown pictures of various women in either sexual or non-sexual poses, whilst they were either exposed or not exposed to the scent of the sexually aroused women. The researchers found that the men inhaling the scent would increase their attention and declare themselves more likely to pursue the women in sexual poses, but would not show any greater attention than the placebo group when it came to the photos of women in non-sexual poses.

In three experiments, axillary perspiration samples were collected from female donors while they were sexually aroused and (at a diferent time) while they were non-sexually aroused; then,
male recipients were exposed to each of these scent samples. Experiment 1 tested the hypothesis that males would evaluate the scent samples of sexually aroused females as more attractive than the non-sexual scents. Experiment 2 tested whether exposure to the sexual scent samples would increase males’
sexual arousal. Finally, Experiment 3 explored whether female sexual chemosignals augmented men’s attention to female sexual cues in a subsequent task. Specifcally, in Experiment
3 it was examined whether exposure to sexual arousal scents would lead males to spend more time viewing photographs of scantily dressed women in seductive poses and report a greater
motivation to pursue these women.

https://link.springer.com/content/pdf/10.1007/s10508-019-01588-8.pdf

The researchers concluded that their initial hypothesis, which appears to have been based upon evolutionary psychology, that men (who have less mating choices than women) would have an evolutionary advantage in being able to pick up olfactory cues as to a female’s willingness to mate, was confirmed by the experiments.

Note that the research paper uses the term ‘chemosignals’, which is a general word used to describe purported molecules that can transmit emotional information about one individual to another. The word for these molecules when in the context of sexual signals is pheromones, but this term is still unfortunately highly contentious at this time in the scientific community.

The experiments made no attempt to determine what the particular ‘chemosignals’ or pheromones, which were present in the sweat of the sexually aroused females, and responsible for the men’s greater sexual attention were. Undoubtedly, though, it serves as further proof that pheromones are a real thing in humans, just as they are with virtually all other animals, even if the precise mechanism in which they work in humans is yet to be established.

One purported female pheromone that is likely secreted through sweat glands is estratetraenol. Known to be produced via the ovaries, it is suspected to be also found in female urine and sweat, and long been considered the most likely candidate for a female pheromone. Many of the top pheromone sprays for women contain it, including my best rated female pheromone spray ‘True Sexiness‘.

Recently Discovered Darcin Pheromone ‘Puts Female Mice In The Mood’

A pheromone in mice that was only discovered by researchers ten years ago, has been shown to ‘put female mice in the mood’ – but only if the ‘complex’ internal state of the mouse allows it.

Just as with discoveries made regarding the ‘love hormone’ oxytocin, this new research, published this week in the prestigious Nature journal, may point to pheromones having a more complex role in attraction than was previously assumed. Some of the mice exposed to the pheromone – named ‘Darcin’ after the Jane Austen character Mr Darcy – reacted with immediate attraction, while others ignored it.

In a new paper, researchers from Columbia University’s Zuckerman Institute describe how different female mice reacted in the presence of urine that contained darcin.

The majority of mice showed an immediate attraction to the urine—in some cases, even reciprocating by offering their own urinary markings in return. Other behaviors reported in the study include singing in frequencies higher than the human ear can pick up. This also indicates a high sex drive, the researchers say.

However, this reaction to the darcin was not universal. Some mice appeared to ignore the darcin. In particular, the researchers noted, females who were lactating seemed oblivious to the presence of the pheromone.

The researchers suspect the mechanism behind these varied reactions lies in the medial amygdala, a part of the brain that plays a key role in the processing of social stimuli and, crucially, social odor cues.

..The study’s authors suspect there could be other pheromones that are processed in a similarly complex way.

Sources include : https://www.newsweek.com/sex-pheromone-named-after-mr-darcy-found-put-female-mice-mood-1484678

The importance of this new research into the power of pheromones is that it adds to the weight of evidence that these ‘love molecules’ do in indeed play a key role in sex and sexual attraction between mammals, including by extension humans. The problem is that such experiments as the one described above into ‘Darcin’ are much easier to conduct in mice, than in people.

The Power of Oxytocin

Oxytocin is a naturally occuring hormone that has long been associated with pregnancy and breast feeding in women. Scientists suspected that it may have a role in the bonding that occurs between a mother and her new born child, and this – as well as a wider role in social bonding in general – was first confirmed in a 2003 study1 involving prairie voles. The levels of oxytocin in these famously monogamous mammals was found to increase in the brain of the female vole during sex with its partner.

Since that noted study, countless other research teams have explored and confirmed further the role of oxytocin in bonding, empathy, trust, and even sexual attraction. These findings, often reported in the mainstream media and press, have given oxytocin the popular tage of the ‘love hormone’, the ‘cuddle hormone’, or the ‘trust hormone’. But to complicate matters, several studies appear to have suggested that the love hormone may have a darker side – among other things, possibly reinforcing ingroup and outgroup preferences, potentially being a cause of racism.

The Wikipedia page for Oxytocin gives a very good overview, as well as this interesting LiveScience article on 11 interesting effects of oxytocin.

[1] Vacek, Marla (2002). “High on Fidelity: What can voles teach us about monogamy?”. American Scientist.

Does Oyxtocin Increase Social Awareness in Autistic Patients?

Oxytocin has hit the headlines in recent years as the role of the hormone in social bonding has been repeatedly confirmed by scientific researchers. Quickly nicknamed the ‘love hormone’ or the ‘cuddle hormone’, the race is now on to investigate whether the seemingly magical social bonding powers of oxytocin could form the basis for a medical treatment to those suffering from social functioning deficits – particularly autism.

Larry J Young was one of the first researchers to examine oxytocin in relation to social bonding, and like other early research attempts, this was done through studying the behaviour of famously monogamous prairie voles. Young, and others, discovered that oxytocin appears to play a major role in prairie vole monogamy. This built on early knowledge that oxytocin (a primarily female hormone) played in an important role in child birth and the bonding between a mother and her new born child.

Young believes that oxytocin could be used to help autistic children improve their social functioning, in addition to more traditional means such as behavioural therapy, as he explained in an interview published this week.

The animals I studied, prairie voles, form strong bonds. Once a male and a female pair up, that partner is very rewarding to them and they want to be with that partner. This also involves oxytocin. In terms of pair bonding, oxytocin enhances the signal of the partner, allowing it to reach the reward center of the brain essential for linking the neural encoding of the partner to reward.

How does this relate to autism?
Young: Children with autism have difficulty in interpreting emotions in others. The idea is that oxytocin could enhance their attention to the social information around them. One of the deficits in autism is that social information is not that salient to these patients; they’re not drawn to someone’s eyes like most of us are drawn to the eyes. Some studies have shown that they have difficulty recognizing faces, they have difficulty interpreting emotions in others. The idea is that oxytocin will enhance their attention to the social information around them, helping them to navigate in the social world.

In acute studies, researchers have given oxytocin to patients with autism and evaluated whether it helps them read emotions better. However, the effect is very short — an hour later, the oxytocin is gone. In studies on chronic use, oxytocin is given every morning and evening. The problem with that is, if you give a child oxytocin before you send them off to school, it may intensify the experience of negative social stimuli. Kids can be mean; kids bully. So, we’ve suddenly turned up the ability of these kids’ brains to pay attention to others around them, and that might not be a positive experience. That’s the mistake of the recent trials that have been done. If you view oxytocin as enhancing the salience of social stimuli, then you want to control those social stimuli.

You can read the full interview here.