Fairness & Cooperation in the Brain

Fairness and cooperation

Fairness and cooperation are interesting concepts to look into particularly in brain science because these are human abilities that affect our whole society.

Social scientists have been studying strategic decisions for decades now. In the 1950’s a classic strategy game was developed called the Prisoner’s Dilemma. Two people play the role of criminals and are interrogated independently. If both are silent (cooperate) the both benefit. However if one confesses (defect), harsh punishment may result. Each partner can try to minimize their own punishment bit without knowing what the other person intends to do.
In an economic variation of this game player’s each have an item of worth but each values the item of the other person more than their own. So simply if they both exchange both stand to gain however if one defects and keeps both then one is empty handed and the other takes all.

With the advent of brain imaging we can now look into the brain and see what is happening during these games. Interestingly, and maybe logically, when cooperation occurs we can se activation in the striatum. The striatum is deep in the limbic system and is part of the basal ganglia which, amongst others, is active in processing reward in the brain. Simply meaning cooperation is rewarding i.e. makes us feel good!
An interesting aspect of this is that when faced with computers rather than another human being the striatum did not activate suggesting that human cooperation creates a good feeling but not through cooperation with abstract objects or machines. Our inbuilt human connection ability.

In addition to this the concept of fairness seems also to be inbuilt into humans. A classic experiment gives one player a sum of money – say 1 dollar. This person can then split this with another person – if the other person agrees then both keep their share if the other person disagrees then both lose the money. Now logically the person without any money should accept any offer because they stand to gain whatever and the person with the money stands to “lose” however this is not what happens. The person accepting the money will refuse I they perceive it is unfair which seems to be around 30% below this and it is perceived as unfair.

Taking this concept of fairness to the Prisoner’s Dilemma if defectors were punished (financially) this also activated the striatum – again giving a sense of reward. And the more a person chose to donate to charity the more the striatum activated also giving a sense of reward. Note this was not the same as physical punishment, which did not activate the striatum.

Research with people with brain lesions also give powerful indicators of how different areas can affect processing. People with intact brains will accept fair offers and reject unfair ones. However people with damage to their ventromedial prefrontal cortex, an area important in cognitive control, rejected more offers than others do. In contrast researches temporarily inactivated the right dorsolateral prefrontal cortex and found that they accepted more unfair offers.

So what?
Cooperation is rewarding
Cooperation is not rewarding with machines (vs. human beings)
Punishing defectors financially is rewarding
We have inbuilt fairness concepts and will reject offers we feel are unfair.
Areas of the prefrontal cortex influence our ability to process fairness.

This is very relevant in many areas of business and the economy: for example the whole discussion around executive bonuses is more a discussion of how we perceive fairness rather than actual quantity of bonus.