Archive for the ‘Biology Letters’ Category

Pedophiles’ brains are “abnormally tuned” to find young children attractive, according to a new study published this week. The research, led by Jorge Ponseti at Germany’s University of Kiel, means that it may be possible to diagnose pedophiles in the future before they are able to offend.

The findings, published in scientific journal Biology Letters, discovered that pedophiles have the same neurological reaction to images of those they find attractive as those of people with ordinary sexual predilections, but that all the relevant cerebral areas become engaged when they see children, as opposed to fellow adults. The occipital areas, prefrontal cortex, putamen, and nucleus caudatus become engaged whenever a person finds another attractive, but the subject of this desire is inverted for pedophiles.

While studies into the cognitive wiring of sex offenders have long been a source of debate, this latest research offers some fairly conclusive proof that there is a neural pattern behind their behavior.

The paper explains: “The human brain contains networks that are tuned to face processing, and these networks appear to activate different processing streams of the reproductive domain selectively: nurturing processing in the case of child faces and sexual processing in the case of sexually preferred adult faces. This implies that the brain extracts age-related face cues of the preferred sex that inform appropriate response selection in the reproductive domains: nurturing in the case of child faces and mating in the case of adult faces.”

Usually children’s faces elicit feelings of caregiving from both sexes, whereas those of adults provide stimuli in choosing a mate. But among pedophiles, this trend is skewed, with sexual, as opposed to nurturing, emotions burgeoning.

The study analyzed the MRI scans of 56 male participants, a group that included 13 homosexual pedophiles and 11 heterosexual pedophiles, exposing them to “high arousing” images of men, women, boys, and girls. Participants then ranked each photo for attractiveness, leading researchers to their conclusion that the brain network of pedophiles is activated by sexual immaturity.

The critical new finding is that face processing is also tuned to face cues revealing the developmental stage that is sexually preferred,” the paper reads.

Dr. James Cantor, associate professor at the University of Toronto’s Faculty of Medicine, said he was “delighted” by the study’s results. “I have previously described pedophilia as a ‘cross-wiring’ of sexual and nurturing instincts, and this data neatly verifies that interpretation.”

Cantor has undertaken extensive research into the area, previously finding that pedophiles are more likely to be left-handed, 2.3 cm shorter than the average male, and 10 to 15 IQ points lower than the norm.

He continued: “This [new] study is definitely a step in the right direction, and I hope other researchers repeat this kind of work. There still exist many contradictions among scientists’ observations, especially in identifying exactly which areas of the brain are the most central to pedophilia. Because financial support for these kinds of studies is quite small, these studies have been quite small, permitting them to achieve only incremental progress. Truly definitive studies about what in the brain causes pedophilia, what might detect it, and what might prevent it require much more significant support.”

Ponseti said that he hoped to investigate this area further by examining whether findings could be emulated when images of children’s faces are the sole ones used. This could lead to gauging a person’s predisposition to pedophilia far more simply than any means currently in place. “We could start to look at the onset of pedophilia, which is probably in puberty at about 12 or 14 years [old],” he told The Independent.

While Cantor is correct in citing the less than abundant size of the study, the research is certainly significant in providing scope for future practicable testing that could reduce the number of pedophilic crimes committed. By being able to run these tests and examine a person’s tendency toward being sexually attracted to underage children, rehabilitative care and necessary precautions could be taken to safeguard children and ensure that those at risk of committing a crime of this ilk would not be able to do so.

http://www.thedailybeast.com/articles/2014/05/23/study-finds-pedophiles-brains-wired-to-find-children-attractive.html#

paul-newman-still-130327

Despite a known link between a masculine-looking face and aggression in men, macho-faced soldiers didn’t survive Finland’s World War II Winter War in greater numbers than recruits with less masculine faces.

The macho-looking men did, however, have more children in their lifetimes than thinner-faced guys, suggesting that face shape is a sign of evolutionary fitness.

The new findings, published today May 7 in the journal Biology Letters, reveal nuances in how hormones, genetics and societal structures might work together to influence evolution. For example, the technology of 20th-century warfare may have turned survival into a matter of luck rather than evolutionary fitness, said study leader John Loehr, an evolutionary ecologist at the University of Helsinki Lammi Biological Station.

“You have very little individual ability to change your fate,” Loehr told LiveScience. “You’re put in a situation where you and the 20 other people who are in your trench are hit by a shell, and it’s game over.”

High levels of testosterone during development are linked with a certain macho look: a broad face, strong jaw and narrow eyes. Any number of swaggering movie stars, from Paul Newman to Channing Tatum (“G.I. Joe”), has parlayed this face shape into successful onscreen careers.

Meanwhile, psychologists have found that guys with Newman’s squint or Tatum’s wide cheekbones tend to be higher in aggression than men with thinner faces. One study on Japanese baseball players, released in April, found that wider-faced players hit more home runs. And in 2008, Canadian researchers discovered that hockey players with wider faces spent more time in the penalty box than other players for aggressive behavior.

The hockey player finding got Loehr thinking about whether high testosterone (and thus, aggression) might confer a survival advantage on wider-faced guys.

“The obvious thing, for me, was, ‘Well, can we get some military data?'” he said.

Fortunately, he could. Finland is a country with meticulous record-keeping, and at the library for the Finnish National Defense in Helsinki, Loehr inquired of a librarian where he might find resources with photos of World War II soldiers (for facial width measurements) as well as personal data about those men.

“She sort of walked around the corner and there were rows of these books sitting there with all the pictures and an amazing amount of personal data,” Loehr said.

Over several months, Loehr pulled together other resources, including photo books of dead soldiers compiled during Finland’s three-and-a-half-month Winter War with the Soviet Union in 1939. Using these old books, he was able to measure facial widths of both surviving soldiers and men lost during the war. He also knew these men’s ranks and how many children they had during their lifetimes.

Military service was and still is mandatory in Finland, Loehr said, so World War II soldiers were a good representation of the male population.

Loehr focused on three WWII regiments, for a total of 795 soldiers. He and co-researcher Robert O’Hara of the Biodiversity and Climate Research Center in Germany found that wider-faced soldiers fathered more children than narrower-faced ones. The finding would have been expected by evolutionary researchers, given previous studies suggesting that fertile women are drawn to more masculine men.

The other findings were more surprising. For one, the wider-faced guys were actually less likely than narrow-faced men to rank higher in the military hierarchy. In other words, the higher the rank, the more likely the man was to have a narrow face.

“That’s a curious one,” Loehr said. Ecologically, he said, you’d expect the men who fathered more children in a community to be the socially dominant guys.

“For human species, it’s perhaps more nuanced,” Loehr said. For example, wide-faced guys have been shown in laboratory experiments to be less trustworthy. Trustworthiness might be more important for military leaders than dominance or aggression.

Another possibility is that the wider-faced guys could have moved up the military ranks during periods of conflict, Loehr said, as his findings were based on rank before the Winter War started. A study published in June 2012 found that in competitive situations, macho-faced guys are the most likely to work together to defeat a common enemy. If that’s the case, any testosterone advantage may not have come out until war began.

Second, Loehr and O’Hara found that face shape didn’t affect survival at all. A wider-faced man was equally as likely to die in battle as a man with a narrower face.

Technology may trump testosterone, Loehr said. One study, published in 2012 in the journal Evolution and Human Behavior, found that in fights involving hand-to-hand combat or other physical contact, narrow-faced men were more likely to die than wide-faced men. In conflicts where a gun, poison or other remote weapon was used, face shape made no difference.

The same could be true for Finnish soldiers, who fought and died with guns in the trenches, Loehr said.

“You would think that thousands of years ago, when combat would have been more hand-to-hand, without much use of tools, that you would have a different result,” he said. “It’s possible that humans have changed how selection can operate by developing this technology.”

http://www.livescience.com/29393-macho-faces-war-survival.html

sn-heliocoprion

An ancient fish that sported a saw blade-like whorl of serrated teeth—and was long presumed to be a member of the shark family—actually belonged to a different but closely related group, a new study suggests. Members of the genus Helicoprion were first described in 1899, but fossils have been notoriously incomplete, with most including only spiral groupings of teeth. Although some fossils have also preserved hints of cartilaginous tissue, none have included the braincase or postcranial parts of these fish. Accordingly, scientists never came up with a convincing idea of what these creatures looked like, with some teams suggesting the whorls sprouted from the nose like an elephant’s trunk, and others placing toothy appendages on the creature’s tail, dorsal fins, or drooping from the lower jaw. Now, an x-ray CT scan of a particularly well-preserved fossil unearthed in Idaho in 1950—one that includes 117 teeth, the cartilage on which they were attached, and part of the upper jaw—reveals that the whorl resided within the animal’s lower jaw (artist’s concept above), researchers reported in Biology Letters. The size and shape of the upper jaw fragment suggests that the creature was about 4 meters long, with some other species in the Helicoprion genus measuring almost twice that length. The arrangement of tissues in the animal’s lower jaw, including those previously hidden by the rock that entombs them, definitively shows that Helicoprion is not a shark, the researchers say. Instead, the genus is nestled firmly within a group of cartilaginous fish known as chimaera, a lineage that includes species commonly known as ghost sharks and ratfish.

http://news.sciencemag.org/sciencenow/2013/02/scienceshot-ancient-fish-sported.html?ref=em

Thanks to Dr. Rajadhyaksha for bringing this to the attention of the It’s Interesting community.