One of the most important and surprising things I’ve learned about decision-making is that we rely on, even require gut feelings to make important decisions about the future. Naqiv, et. al. (2006) write about findings in neuroscience that support the somatic-marker hypothesis, which suggests that when we make decisions under uncertainty, we choose among different options based on the different feelings each elicits.
Neuroscientists are doing exciting work illuminating how the brain makes successful and unsuccessful decisions and which areas of the brain are instrumental. One way they do this is by examining people with brain damage. For example, it has been found that people with damage to their ventromedial prefrontal cortex (vmPFC) not only appear emotionless, but also they make very poor personal, ethical and financial decisions. Experiments like the Iowa Gambling Task suggest that people feel what the correct decision is before they are consciously aware of it. People may be unconsciously simulating various options in their mind and re-experiencing the feelings that each option elicited in the past. These feelings occur at such a deep (sub-cortical) level that they elicit an approach or avoid response even when the person is not conscious of the feeling.
The two key brain parts that are involved are the ventromedial prefrontal cortex and the amygdala. The vmPFC is located just above the eye-sockets. It is deeply involved in decision-making by helping people learn from past mistakes and to simulate for each option the feelings that could result in the future. People make very bad ethical, social and personal decisions when this is damaged (see picture below). The amygdala is located deep within the brain and mediates positive and negative emotions on the left and right sides, respectively. It is the amygdala that creates the positive and negative feelings in the first place and works with the vmPFC to allow us to make good decisions in certain circumstances.
The important point for decision-making is that the brain is wired to allow us to make decisions with risk or uncertainty quickly and non-consciously. The classic model of decision making that we learned in traditional economics where people are assumed to make coldly-rational, calculated utility-maximizing decisions is at best only part of the story. Intuition does, in fact, drive a lot of our most important decisions. This is a good thing. Our highest ideals like fairness, honesty, justice, beauty, love and sanctity of life can be neither quantified nor easily incorporated in a utilitarian cost-benefit analysis. If we fail to respect our intuitions, our decisions will fail to respect our humanity.