At Harvard in the early 1960s, Daniel Ellsberg observed what he called ‘ambiguity aversion’ – people might prefer certainty to maximising subjective expected utility.

If people considered the possible negative and positive consequences equally, they might find it hard to take any action. Inevitably they veer toward information that confirms the desired positive result, the rosy scenario, without realizing it. We also see this at work when people are supposedly asking for advice.

technical name is loss aversion—was