optimistic bias

The optimistic bias is an expression used by Daniel Kahneman to describe the idea that "most of us view the world as more benign than it really is, our own attributes as more favorable than they truly are, and the goals we adopt as more achievable than they are likely to be." Furthermore, most of us have an unrealistic view about predicting the future: we think we're much better at it than we really are. Study after study has found that self-deception is pervasive: the vast majority of people think they are above average, less biased, more congenial, less susceptible to improper influence, and more competent than the majority of their peers.

Kahneman thinks that many of us suffer from (or are blessed with, depending on how you see things) "optimistic overconfidence." He writes that "the optimistic bias may well be the most significant of the cognitive biases. Because optimistic bias can be both a blessing and a risk, you should be both happy and wary if you are temperamentally optimistic." (Thinking, Fast and Slow, p. 255).