What is the good life? I interpret the question in terms of what contributes to our success as agents. Assuming that we are lucky enough not to have to devote all of our mental and physical energy to escaping death or avoiding suffering, what enables us to acquire and preserve the motivation to pursue and achieve the goals we set for ourselves? Why do we persist, in the face of initial failures and arduous challenges? Resilience and determination is often explained by a belief in something greater than us that inspires them. Alternatively, praise is given to an agent’s personality that makes her bounce back from defeats and never give up. And to be sure, it is easier to overcome the inevitable obstacles that might ariseif a supportive social network can be relied on. There is something plausible in all the explanations above. But what if the secret of our perseverance were an all-too-common bias?

I want to suggest that it is our pervasive irrationality that in some circumstances contributes to our success. In the last five years, my research has focused on forms of irrational belief that benefit us, making substantial contributions to our success as agents. With my team, I looked at different forms of irrationality, from the unusual ones associated with schizophrenia, amnesia, and dementia, often referred to as delusions and confabulations in the psychological and clinical literature, to the mundane ones, such as the beliefs driven by implicit bias that we are all likely to have. We have also considered different types of benefits, from the psychological ones, usually captured by an increase in wellbeing or good functioning, to the epistemic ones, characterised by enhanced knowledge or understanding.

___

"Due to positive illusions, we are likely to adopt false beliefs and rely on unfounded predictions. However, such failings are instrumental to our living a good life."

___

There is one manifestation of our irrationality that is found to be beneficial for us from different perspectives, and that is our vulnerability to positive illusions. We tend to believe that, when it comes to how good we are, to what extent we can control events in our life, and how successful we will be in the future, things are better than they actually are. For instance, we experience the optimism bias when we significantly underestimate the possibility of getting a divorce or experiencing serious illness in the course of our lives. Furthermore, we are ready to update our beliefs and revise our expectations when we receive good news, coming to see ourselves as better and as more likely to succeed than previously thought. However, we discount evidence suggesting that we are set up for failure when we receive bad news.