Equilibrium in the brain

Economists talk about equilibrium in markets – a balance between supply and demand that is sensitive to external factors like increased production and weakened consumption. It seems to me they should also talk analogously about equililrium in the brain.

 

To paint a crude picture: the brain is an evolved hotch-potch of the primitive brain stem (responsible for automatic responses such as flinching when a fast-moving object approaches one’s head), the emotional or limbic system (responsible for affective responses like fear and disgust, as well as predictive systems that constantly seek to identify patterns in the world, and memory and learning), and the most recently evolved neo-cortex (responsible for controlled rational deliberation).

 

Western philosophy has always thought that it is the equilibrium between the rational neo-cortex and the ‘irrational’ emotional brain that counts. But it is not the case, as Plato and many other philosophers have argued, that the rational brain lords it over the emotional. In fact, the latter is a highly developed and amazingly efficient super-computer, whereas the former is a weak, cheap calculator in comparison.

 

The emotional brain can run parallel processes, is incredibly fast, and the more it is used the stronger it gets: if we feel good about getting a certain reward our sensitivity for detecting that reward is heightened and our ability to detect it is strengthened. Conversely, the rational brain can only run processes in series, is slow, and is only able to hold a small amount of information in mind. In addition, the more we use the rational brain the weaker it gets. For example, if someone exercises self-control via the neo-cortex, then her ability to exercise it immediately afterwards drops off considerably (the rational brain tires very quickly).

 

Given all this it is not really the case that the equilibrium of the brain that counts the most for us humans is that between rational and emotional systems. That equilibrium is important, but the equilibrium within the emotional system is more so, as the latter handles the vast majority of processing work.

 

Again, to paint a very crude picture, the emotional propensities that constitute the equilibrium in the emotinonal brain relevant to decision-making and behaviour are the following: the ability to feel in control of one’s life; the ability to apply oneself; the desire for immediate reward; a sense of fairness; the ability to act altruistically; the ability to empathise concernfully with others.

 

Arguably, all these emotional propensities are evolved functions that ensure both personal success and group cooperation and cohesiveness. They are a subset of Keynes’ ‘animal spirits’.

 

But because they are only propensities they can be more or less prominent in the functioning of the brain. A simple way to categorise them is as individualistic and social concerns. And just like equilibria in markets, equilibria in brains will change in relation to external forces: if society is organised along individualistic lines our brains will reflect that, and vice versa.

 

The good news is that the brain is very plastic (which is why externalities can affect its equilibrium), and although rebalancing it is not easy, it is not impossible either. So if we want the good society to be less individualistic and more ‘pro-social’, we educate and train ourselves along those lines.

 

At the moment neuro-economists tend to fall into two camps. The first is  concerned with social policy and sets about understanding the way the brain works in order to bring about specific social outcomes like increased savings for pensions. The second is concerned with supplementing classical economics with information about how the brain’s ‘irrational’ tendencies influence the equilibria of markets.

 

But what if neuro-economics were to be concerened with the equilibrium of the brain – that is, the proportion in which the various emotional propensities described above are balanced, and the external influences that shape that balance? Such an economics would measure the effects of things like social capital, genetics, inequality, gender and well-being on the capabilities of individuals to behave in certain ways. But perhaps most important, it would serve as a means to calibrate the equilibrium of the brain into one that reflects the kind of society we want.