A paper in this week’s Proceedings of the National Academy of Sciences demonstrates that the brain structures of naked mole rats, which live in ant-like colonies with many non-breeding “subordinates” working to support a few dominant “breeders”, change based on their social status. Mole rat subordinates taken out of a colony and offered a mate effectively become breeders, starting their own colony – and when this happens, certain regions of their brains get bigger. This effect is apparently larger than the difference between mole rat male and female brains.

Social control of brain morphology in a eusocial mammal (PNAS 104:10548-52)