Primate brains might have evolved to 'catch up' with larger bodies, but then kept growing‎

A new analysis supports the previously overlooked "brain lag" hypothesis—the idea that, in some primate lineages, the evolution of larger body size preceded the evolution of larger brain size—while also building on that hypothesis by suggesting that some lineages' brain sizes then continued to grow beyond an expected baseline. Robin Dunbar of the University of Oxford presents these findings in the open-access journal PLOS One.