HOW BIG IS YOUR NETWORK

Although the average social network contains around 150 friends, there is considerable individual variation. Some people have fewer than 100 relationships, a few may have 250 or more. There are three main reasons for this: gender, social skills and personality.

Social skills are important in juggling the complex and ever-changing world of social relationships. They seem to depend on theory of mind or mentalising -- the ability to understand another person's perspective. People's ability at these skills varies, and it turns out that the number of best friends we have correlates with this. Since women tend to be better at mentalising than men, it is perhaps no surprise that they often have larger social circles than men.

Personality plays an important role, too. For example, people who score high on the neuroticism dimension of the big five personality dimensions have fewer friends than those who score low. As might be expected, extroverts have larger social circles than introverts -- and this is true at each of thenetwork layers. Despite being more social, however, extroverts are not emotionally closer to members of their network than introverts. It seems we have a limited amount of social capital and can either spread it thickly among a few friends or thinly among many. Extroverts opt for the second because they are willing to put in the time and effort required to look after many relationships.

SOCIAL NETWORKS. By: Dunbar, Robin, New Scientist, 02624079, 4/7/2012, Vol. 214, Issue 2859