Tag Archives: male

Women undoubtedly prefer strong, muscular men, study shows

Psychologists have confirmed something most women deep down know regarding male physical attractiveness: strong men are, by far, preferred to weaker looking men.

The study was based on interviews with 160 women. The female participants had to rate the physical individual attractiveness of men from two categories: a group composed of 130 psychology students and one composed of 60 gym-going university students who worked out a few times per week.

Aaron Sell, a psychology lecturer at School of Criminology and Criminal Justice, Griffith University, Australia and his co-author, Aaron Lukaszewski, an evolutionary psychologist at California State University at Fullerton measured the males’ strength via weightlifting machines, grip strength tests and other methods.

Source: Pexels/Pixabay

The male recruits all came from the University of California at Santa Barbara. The assessors, students from Oklahoma State University and Australia’s Griffith University, rated both strength and physical attractiveness on a scale from 1 to 7. Interestingly, the scores the women gave for strength were fairly accurate compared to the actual physical performances of the students.

“The rated strength of a male body accounts for a full 70 percent of the variance in attractiveness,” Sell said.

None of the surveyed women showed a statistically important preference for weaker looking guys.

“No one will be surprised by the idea that strong men are more attractive,” said one of the study authors, Aaron Lukaszewski, told The Washington Post. “It’s no secret that women like strong, muscular guys.”

“That is so obvious, people are going to wonder why scientists needed to study it,” said Holly Dunsworth, an anthropologist at the University of Rhode Island, also to The Post. “And the answer would be because they want to know how these preferences evolved.”

Dunsworth also raised questions about the reliability of the paper, because the study involved only 20-year-olds, who she adds, may not have very much experience with the meaning of attractiveness.

Source: Geralt/Pixabay

Lisa Wade, a sociologist at Occidental College in Los Angeles, also criticizes the study’s interpretation: “It’s my opinion that the authors are too quick to ascribe a causal role to evolution,“ she told The Post.

According to Wade, culture has a bigger impact on male torso aesthetics.

“We value tall, lean men with strong upper bodies in American society. We’re too quick to assume that it requires an evolutionary explanation,” she said. “We know what kind of bodies are valorized and idealized,” Wade added. “It tends to be the bodies that are the most difficult to obtain.”

In her opinion, a few centuries ago, women would have preferred larger torsos, due to the scarcity of hyper-caloric food and the requirements of heavy physical labour. The preference for leaner upper masculine bodies was not universally valued at that time.

The paper published in Proceedings of the Royal Society B surely has many scientists arguing over it, but the team led by Sell and Lukaszewski plans to examine physical attractiveness on a larger scale, with a cross-cultural study on the way.

Birth controll pill for men might be just around the corner

Two drugs, currently prescribed to organ transplant patients to suppress their immune system after the procedure, show great promise as birth-control medicine for men, according to a study published in the journal Science.

Image via express.co.uk

Cyclosporine A (also known as CsA) and FK506 (also known as tacrolimus) are currently in use with transplant recipients to reduce the risk that their body will reject the new organ. They work by inhibiting their body’s ability to synthesize a protein that mobilizes T-cells to attack. More specifically, they block the enzyme called calcineurin. And this ability is exactly what makes them promising as male birth-control.

By studying mice, researchers in Japan identified a version of calcineurin that is found only in sperm, built from a pair of shorter proteins — PPP3CC and PPP3R2. They created male mice that were unable to produce PPP3CC (and thus naturally produce less PPP3R2). Then they studied these “knockout” mice to see how they differed from their unaltered fellows.

They found that the knockout mice still had sex, but the females didn’t become pregnant. The absence of PPP3CC must be making the males infertile, the researchers figured, then set about figuring out why. The sperm got where they were needed — researchers found that sperm from the knockout mice were able to reach the part of the ovary where fertilization usually takes place. They noted that the number of sperm was lower than in regular mice, but not low enough to explain the infertility.

So they tried giving the little swimmers some help, and performed in vitro fertilization using sperm from the knockout mice. They were unable to fertilize an egg as long as the it was covered by its usual layer of cumulus cells, but it wasn’t the cumulus cells that were the problem. In further tests, the researchers found that the sperm could make their way through these cells and bind to the zona pellucida, or ZP, the membrane that surrounds the egg. But that was as far as they could go.

What kept the sperm from getting through the ZP? The knockout sperm were able to move at the about same velocity as the regular sperm, the researchers found. However, the knockout sperm were deficient at something called “hyperactivation.” This is a particular type of movement that requires the sperm’s whiplike tail to beat back and forth with extra force.

But the Japanese researchers wanted to know more. They found that the tails of the knockout sperm moved with the same frequency as those of the unaltered mice, but the part that connects the tail to the head was too rigid. This made the entire sperm cell too inflexible to move with enough force to penetrate the ZP, the researchers concluded. To make sure this was the true bottleneck, they used IVF again, to see whether knockout sperm could fertilize eggs once the ZP was gone. They could, and the fertilized eggs developed all the way to term.

Then the research team gave the immunosuppressant drugs to regular mice, to see whether their sperm would turn out like the sperm of the knockout mice. The drugs had no effect on mature sperm cells, which were just as flexible as ever, but worked better on sperm that were still developing. Regular male mice that got either CsA or FK506 for two weeks became infertile, because the middle part of their sperm was rigid. Further tests showed that it took only four days for FK506 to render the mice infertile, and five days for CsA to do the same.

When the mice stopped taking the drugs, their fertility returned after one week.

“Considering these results in mice, sperm calcineurin may be a target for reversible and rapidly acting human male contraceptives,” they concluded.

Deceptive Female Mantises Eat Males Even Without Having Sex

It has been known for quite some time that male praying mantises can get their heads ripped off while copulating with females. But a new study has shown that deceptive females can trick the males and eat them even without copulation; basically, they lure them in pretending to be full of eggs and eat them when they’re hungry.

“This is the first evidence in support of the Femme Fatale hypothesis, which posits that female mantids in poor condition might dishonestly entice males in order to eat them rather than mate with them,” said lead research Dr Kate Barry, of Macquarie University’s Department of Biological Sciences.

The study initially found that males are more attracted to starving females, despite the chance of being eaten during copulation.

mantis

Image via 5oclockam.

 

“We presume this attraction is due to an increase in the quality or quantity of pheromone emissions, which makes sense because very hungry females gain both survival and reproductive benefits from attracting and consuming a male.

They then observed that some females (which are much larger than the males) eat the males even without reproduction. They set up large large field enclosures on the Macquarie University campus to examine the potential for sexual deception in females.

They found that healthy, well fed females sometimes lure in males with no intention of reproducing, just to eat them. However, hungry females are much more likely to do this. To figure this out, researchers assigned 24 female to one of four feeding regimes: good, medium, poor, or very poor, for six weeks. The cages were covered with two layers of mesh so that you couldn’t see inside of them, but chemical signals could still be released. 78 virgin males were then released and out of them, 55 were found on female cages. The number of males found on specific cages was used as an indicator of female attractiveness.

This is the first time that females exploiting males has  been reported in nature… and it’s also the most extreme example of sexual manipulation ever found.

“There are many examples in the animal kingdom of males exploiting females to secure paternity, however in this instance, female praying mantids have turned the tables.”