Determined: A Science of Life without Free Will

by Robert M. Sapolsky

The same unsettling conclusion comes from neuroimaging studies. If someone makes you an unfair offer in the Ultimatum Game, your insula, anterior cingulate cortex, and amygdala activate, a picture of disgust, pain, and anger. The lowball offer puts you at a split in the road. If it’s a single-round game, punish retributively or be purely logical and accept the offer that is better than nothing? The more activation of your insula and amygdala, and the more pissed off you report being by inequity in general, the more likely you are to reject the offer. This retributive irrationality is all about emotion—if people believe they are rejecting an unfair offer from a human rather than a computer, there is also activation of that emotional vmPFC; making a similar point, men with higher testosterone levels are more likely to reject such offers.[28]