A small study has found that the brains of men and women are wired differently in a region that is related to speech, memory, and hearing. Researchers studied the brain tissue from four men and four women who were all having a small portion of their brains excised as a treatment for epilepsy. They found that in the brain region called the temporal neocortex, men have a higher density of synapses, which are the connection points between brain cells.
For many years, scientists have searched for structural variations between men’s and women’s brains to explain psychological studies showing that, overall, the sexes think and act differently. Past studies found differences in brain mass and neuron density, but “they were hyped and untrustworthy,” [neuroscientist Edward] Jones says. This study is meticulously detailed, he notes. It is the first to show gender differences on such a fine scale — at the synapse [Science News].
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It seems that the long debate over whether boys are naturally better at math than girls can finally be put to rest. Researchers examined the standardized test scores of over 7 million students in grades 2 through 11, and found no difference in performance between girls and boys.
They also checked to see if a gender gap appeared in high school, as had been shown in a study 20 years ago. But researchers found no difference in scores among today’s students, which they attributed to an increased number of girls taking advanced math classes. “Now that enrollment in advanced math courses is equalized, we don’t see gender differences in test performance,” said [study coauthor] Marcia C. Linn…. “But people are surprised by these findings, which suggests to me that the stereotypes are still there” [The New York Times].
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On a scattering of small islands off the north coast of New Zealand, members of an ancient reptile species are currently scuttling around, oblivious to the impending doom that researchers predict for them.
Like many reptiles, the tuatara’s sex is determined by the nest temperature while the embryo is developing; now researchers have used computer modeling to determine that global warming could raise island temperatures to the extent that the nests will produce only male hatchlings by 2085. As temperatures tick upwards, the male tuatara will be increasingly desperate and dateless [Australian Broadcasting Corporation].
The study, which was published in Proceedings of the Royal Society B [subscription required], could be the model for studies of lizards and marine turtles with similar reproductive systems. “Since the mid 1990s, people have been talking about the vulnerability of reptiles to climate change because they have temperature-dependent sex determination. But no one has been able to model it in this type of complexity before,” says research leader Nicola Mitchell of the University of Western Australia in Perth [Nature News].
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