Monkeys with larger friend networks have more gray matter

Nov 04, 2011 by Lin Edwards report
Barbary Macaques (Macaca sylvanus) at a monkeys park in Algeria

New research in the UK on rhesus macaque monkeys has found for the first time that if they live in larger groups they develop more gray matter in parts of the brain involved in processing information on social interactions.

The researchers, led by Jerome Sallet of Oxford University, said the results of the new study bear some similarities to research by other groups working with humans, that related to the extent of social interactions. These studies include recent work that suggested a link between the volume of some regions of the brain and the number of online friends people have in such as Facebook.

The new study observed 23 macaques in a number of groups of different sizes. The monkeys were kept in their groups for an average of over a year, and a minimum of two months. One monkey was alone in its cage, but in all the other groups, which had from two to seven individuals, a heirarchy developed in which an individual's rank depended on the monkey's ability to form successful social interactions, such as friendships and partnerships.

The study used (MRI) to compare the brains of the monkeys, and the results showed that in the temporal areas of the brain associated with social interaction skills, around a five percent increase in the volume of gray matter was found for each additional group member. The regions of the brain that increased in volume included the temporal pole, temporal cortex, and the inferior and rostral temporal gyri.

The researchers also compared the brains of male monkeys at various levels in the dominance-based heirarchy and found a number of brain areas, particularly the and inferior temporal sulcus, were enlarged in males of higher rank.

The research demonstrated that the social networks caused the changes in the brain (rather than enlarged influencing position in the social network, or the size of the network) because the scientists manipulated the size and makeup of the groups over a period of several months, and observed the changes in the brains of the monkeys.

Earlier research has shown that the brain shows plasticity, which means it can change in volume in different regions in response to environmental changes or acquisition of new skills or knowledge. Research had not previously shown brain plasticity in relation to social networking skills.

The paper was published in the journal Science on 4th November.

Explore further: New study finds university health schools' use of holistic admissions has positive impact

Related Stories

Monkeys' grooming habits provide clues to how we socialise

Sep 30, 2009

(PhysOrg.com) -- A study of female monkeys' grooming habits provides new clues about the way humans socialise. New research reveals a link between the size of the neocortex in the brain, responsible for higher-level ...

Subordinate monkeys more likely to choose cocaine over food

Apr 06, 2008

Having a lower social standing increases the likelihood that a monkey faced with a stressful situation will choose cocaine over food, according to a study at Wake Forest University School of Medicine. More dominant monkeys ...

Brain biology may dictate social networks

Jan 04, 2011

(PhysOrg.com) -- A new study by a Northeastern University researcher and her colleagues indicates that the size of a certain part of the human brain plays a significant role in determining the breadth of social ...

Recommended for you

Recessions result in lower birth rates in the long run

14 hours ago

While it is largely understood that birth rates plummet when unemployment rates soar, the long-term effects have never been clear. Now, new research from Princeton University's Woodrow Wilson School of Public ...

Human trafficking, an invisible problem

18 hours ago

Human trafficking is a problem about which little is known in Spain, due to both the lack of reliable figures as well as the poor coordination among international police forces and the social permissiveness with regard to ...

The scarring effects of primary-grade retention?

Sep 26, 2014

An article released by Social Forces titled, "The Scarring Effects of Primary-Grade Retention? A Study of Cumulative Advantage in the Educational Career" by Megan Andrew explores the effect of scarring in the educational career ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

RobertKarlStonjek
1 / 5 (1) Nov 04, 2011
OK, next time a rhesus wants to friend me on Facebook I'll say yes ~ his/her grey matter depends on it!!!