Why our brains are large

In today's excerpt - Martin Seligman, the University of Pennsylvania professor whose research has led to the development of the field of positive psychology, comments on the purpose of our large brains and speaks to the importance of relationships with others as one of the keys to our well-being:

"Other people are the best antidote to the downs of life and the sin­gle most reliable up. ... My friend Stephen Post, professor of Medical Human­ities at Stony Brook, tells a story about his mother. When he was a young boy, and his mother saw that he was in a bad mood, she would say, 'Stephen, you are looking piqued. Why don't you go out and help someone?' Empirically, Ma Post's maxim has been put to rigorous test, and we scientists have found that doing a kindness produces the single most reliable momentary increase in well-being of any exercise we have tested. ...  

  

"Is there someone in your life whom you would feel comfortable phoning at four in the morning to tell your troubles to? If your answer is yes, you will likely live longer than someone whose answer is no. For George Vaillant, the Harvard psychiatrist who discovered this fact, the master strength is the capacity to be loved. Conversely, as the social neuroscientist John Cacioppo has argued, loneliness is such a disabling condition that it compels the belief that the pursuit of relationships is a rock-bottom fundamental to human well-being. ...

  

"Two recent streams of argument about human evolution both point to the importance of positive relationships in their own right and for their own sake. What is the big human brain for? About five hundred thousand years ago, the cranial capacity of our hominid ancestors' skulls dou­bled in size from 600 cubic centimeters to its present 1,200 cubic centi­meters. The fashionable explanation for all this extra brain is to enable us to make tools and weapons; you have to be really smart to deal instrumentally with the physical world. The British theoretical psy­chologist Nick Humphrey has presented an alternative: the big brain is a social problem solver, not a physical problem solver. As I converse with my students, how do I solve the problem of saying something that Marge will think is funny, that won't offend Tom, and that will per­suade Derek that he is wrong without rubbing his nose in it? These are extremely complicated problems -- problems that computers, which can design weapons and tools in a trice, cannot solve. But humans can and do solve social problems, every hour of the day. The massive pre­frontal cortex that we have is continually using its billions of connec­tions to simulate social possibilities and then to choose the optimal course of action. So the big brain is a relationship simulation machine, and it has been selected by evolution for exactly the function of design­ing and carrying out harmonious but effective human relationships.

"The other evolutionary argument that meshes with the big brain as social simulator is group selection. The eminent British biologist and polemicist Richard Dawkins has popularized a selfish-gene the­ory which argues that the individual is the sole unit of natural selec­tion. Two of the world's most prominent biologists, unrelated but both named Wilson (Edmund O. and David Sloan), have recently amassed evidence that the group is a primary unit of natural selection. Their argument starts with the social insects: wasps, bees, termites, and ants, all of which have factories, fortresses, and systems of communication and dominate the insect world just as humans dominate the vertebrate world. Being social is the most successful form of higher adaptation known. I would guess that it is even more adaptive than having eyes, and the most plausible mathematization of social insect selection is that selection is done by groups and not by individuals.

"The intuition for group selection is simple. Consider two primate groups, each made up of genetically diverse individuals. Imagine that the 'social' group has the emotional brain structures that subserve love, compassion, kindness, teamwork, and self-sacrifice -- the 'hive emotions' -- and cognitive brain structures, such as mirror neurons, which reflect other minds. The 'nonsocial' group, equally intelligent about the physical world and equally strong, does not have these hive emotions. These two groups are now put into a deadly competition that can have only one winner, such as war or starvation. The social group will win, being able to cooperate, hunt in groups, and create agricul­ture."

Flourish: A Visionary New Understanding of Happiness and Well-being

by Martin E. P. Seligman by Free Press

 

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