Humans are proud of their brains, and rightfully so. A new comparative analysis suggests however, that we should not be so obsessed with size when considering our smarts.
This week evolutionary anthropologists Robert Barton and Chris Venditti report the results of a wide analysis in PNAS Early Edition comparing human frontal lobe size to other brain structures. For an animal our size, our frontal lobes are not larger than expected.
This finding runs counter to conventional wisdom in the popular press and much scientific literature.
“One of the most pervasive assumptions about human brain evolution is that it involved relative enlargement of the frontal lobes,” the authors write. “We show that this assumption is without foundation.”
Prior studies cited as evidence for relative expansion of the frontal lobes, involved in higher-order functioning, have sometimes been based on unscaled measurements. These comparisons confuse selective enlargement with allometric scaling.