PLoS Genet. 4, e1000100 (2008) doi:10.1371/journal.pgen.1000100

How male and female brains differ is debated around the water cooler as much as the lab bench. Working at the latter, Elena Jazin at Uppsala University in Sweden and her colleagues looked for differences in gene-expression patterns in the cortex, which is associated with higher brain functions such as cognition. The team found that some human sex-specific gene-expression patterns are mirrored in the brains of other primates — macaques (Macaca fascicularis) and marmosets (Callithrix jacchus) — and that the sequence of these genes is more conserved than that of a control set of genes.

The fact that these differences are conserved across species suggests that evolution has deemed them worthy of preservation and that they may underlie some differences between the sexes, the authors say. The nature of those differences, however, remains water-cooler fodder.