Monkey leaders and followers have 'specialised brains'

2 September 2014 Last updated at 19:16

By Jonathan WebbScience reporter, BBC News

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.

"We were also looking at learning and memory and decision-making, and the changes that are going on in your brain when you're doing those things," explained Dr MaryAnn Noonan, the study's first author.

The decision to look at the animals' social status produced an unexpectedly clear result, Dr Noonan said.

"It was surprising. All our monkeys were of different ages and different genders - but with fMRI (functional magnetic resonance imaging) you can control for all of that. And we were consistently seeing these same networks coming out."

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Adolescent Male Chimps in Large Community Strive to Be Alphas

ScienceDaily (Sep. 19, 2012) — An Ohio University anthropologist reports the first observation of dominance relationships among adolescent male chimpanzees, which he attributes to the composition of their community. Hogan Sherrow spent eight years studying the Ngogo community of chimpanzees in Kibale National Park in western Uganda. Ngogo is the biggest chimpanzee community on record, with more than 150 members and about twice as many males as found in other chimp communities across Africa.

Unlike their adult male counterparts, which have a well-documented dominance hierarchy, adolescent males have not been known to establish dominance relationships. During four field seasons between 2000 and 2004, however, Sherrow found that some adolescent males pant grunted to other adolescent males on a consistent basis. Research by Jane Goodall established that pant grunts are made by subordinate individuals to dominant ones, Sherrow explained.

Continued:  http://www.sciencedaily.com/releases/2012/09/120920095326.htm