The biology of belief, optimism, and good health Premium

Explore how optimism influences health, survival, and resilience, highlighting its evolutionary benefits and impact on well-being.

Helen Keller, the American author and activist who was deaf and blind, became an international symbol of human potential. She wrote, “Optimism is the faith that leads to achievement. Nothing can be done without hope and confidence.”

Optimism can be defined as maintaining positive expectations for the future. It is a human trait that has also been associated with better health and a higher quality of life. Optimism shapes how we look ahead and functions as a modulator that amplifies positive possibilities and filters out negative projections. The Israeli-British neuroscientist Tali Sharot has estimated that about 80% of humans are optimists but that the optimism levels of most people can be best described as “mild”.

It can be argued that optimism represents a biased view of reality. Why would evolution favour a trait that presents you with a bias instead of a perfectly objective view? The consensus among researchers is that optimism is highly adaptive, meaning it increases an organism’s chances of survival.

Imagine a human as she lived several thousand years ago. She is in a cave and there is a drought going on. If she were to calculate the probability of successfully finding food — a rabbit perhaps, or a bush with edible fruit on it — she would in all likelihood not go out at all. Lethargy, which conserves energy, would be the rational choice. But optimism could encourage her to persist. By overestimating the probability of finding some food out there, she could be more likely to make an effort. This bias gives her an incentive to exert effort, which itself increases the probability of success.

However, there are limits to how optimistic you can be and still make gains. What seems to work best is a general, positive outlook, known as dispositional optimism. In response to a negative outcome in real life, a pessimist may say “I knew it” whereas optimists may resort to the conviction that “tomorrow is another day”. This resilience is maintained through an ‘optimism bias’ (Nature, vol. 450, 102, 2007) characterised by an asymmetric processing of information in the brain: good news is given disproportionate significance and bad news is given less weightage.

One area at the front and centre of the brain, called the rostral anterior cingulate cortex (rACC), is highly active when optimists envision positive future events. High neuronal activity in this region seems to facilitate the encoding of favourable possibilities. Conversely, the rACC’s diminished response to negative information seems to make sure setbacks have less influence on the individual’s long-term expectations.