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: Study finds law dramatically curbing need for speed

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

Study finds law dramatically curbing need for speed

Apr 18, 2014

Almost seven years have passed since Ontario's street-racing legislation hit the books and, according to one Western researcher, it has succeeded in putting the brakes on the number of convictions and, more importantly, injuries ...

Newlyweds, be careful what you wish for

Apr 17, 2014

A statistical analysis of the gift "fulfillments" at several hundred online wedding gift registries suggests that wedding guests are caught between a rock and a hard place when it comes to buying an appropriate gift for the ...

Can new understanding avert tragedy?

Apr 17, 2014

As a boy growing up in Syracuse, NY, Sol Hsiang ran an experiment for a school project testing whether plants grow better sprinkled with water vs orange juice. Today, 20 years later, he applies complex statistical ...

Creative activities outside work can improve job performance

Apr 16, 2014

Employees who pursue creative activities outside of work may find that these activities boost their performance on the job, according to a new study by San Francisco State University organizational psychologist Kevin Eschleman ...

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!!!

More news stories

Egypt archaeologists find ancient writer's tomb

Egypt's minister of antiquities says a team of Spanish archaeologists has discovered two tombs in the southern part of the country, one of them belonging to a writer and containing a trove of artifacts including reed pens ...

Making graphene in your kitchen

Graphene has been touted as a wonder material—the world's thinnest substance, but super-strong. Now scientists say it is so easy to make you could produce some in your kitchen.

Low tolerance for pain? The reason may be in your genes

Researchers may have identified key genes linked to why some people have a higher tolerance for pain than others, according to a study released today that will be presented at the American Academy of Neurology's 66th Annual ...