by JONATHAN WEBB
Macaque monkeys live in groups which have firm social hierarchies
Monkeys at the top and bottom of the social pecking order have physically different brains, research has found.
A particular network of brain areas was bigger in dominant animals, while other regions were bigger in subordinates.
The study suggests that primate brains, including ours, can be specialised for life at either end of the hierarchy.
The differences might reflect inherited tendencies toward leading or following, or the brain adapting to an animal’s role in life – or a little of both.
Neuroscientists made the discovery, which appears in the journal Plos Biology, by comparing brain scans from 25 macaque monkeys that were already “on file” as part of ongoing research at the University of Oxford.
…
In monkeys at the top of their social group, three particular bits of the brain tended to be larger (specifically the amygdala, the hypothalamus and the raphe nucleus). In subordinate monkeys, the tendency was for a different cluster of regions to be bigger (all within the striatum).
Nature plus nurture
At either end of the social ladder, compared to monkeys in the middle, the activity in all these different brain regions was more synchronised. The researchers believe these areas together constitute brain circuits that are crucial for negotiating social situations – interpreting social and emotional cues, learning the value of certain actions, and so on.
BBC for more