Evolution of The Social Brain

The social brain centres around something called Theory of Mind. This is the ability to automatically tune into other people’s emotions and intentions, and this has evolved over many thousands of years. Over the course of human evolution, the human brain has almost trebled in size, and there are chimpanzees today which have the same brain size as the earliest form of human being.

However, there are some costs of humans having a large brain. Because our brain uses 20% of the calories that we consume in an average day, this means that we have to have a highly nutritious diet which can often be hard to find. In addition to this we have painful and dangerous childbirth and a long period of infant dependancy on the parents, which means that once we decide to have a child, we have to remain loyal to that decision for a great number of years.

If you want to measure theory of mind in children, you would use something called the false belief task, which you should be able to find using a quick internet search. It is thought that theory of mind develops around the age of 3-5 years old, so you could use this test to see if your child was developing at the pace that they were supposed to be. It is impaired in autism, so this might be one of the earliest indicators that you can look out for. 

In adults, you can use the “mind in the eyes” task by somebody called Baron-Cohen. This is a task in which you have to look at some photos of people’s eyes and then try to guess the emotion that they were conveying at the time that the photo was taken. If you score lower than 20 out of 36 on this task then you may show tendencies towards autism yourself. It is often found that women would score more highly in this task than men because they do actually tend to be more socially intelligent. Interestingly, over eight times as many men are autistic than women, and this statistic would certainly suppot the theory that women are more socially intelligent. 

So, why is it important to have a social brain? Well, if you think about long into the past, when human beings were only just evolving, you can see that there were a lot of pressures on them before they were able to survive. They had to find food, and they had to make sure that they were able to look after their family. If they couldn’t do this then they wouldn’t be able to survive, so this means that they would benefit from being able to guess what other people were thinking and feeling, as they would be able to work out what their intentions were.

If the social brain had not developed, it is unlikely that our species would have survived at all.