We all have irrational fears – flying is plainly scarier than getting in a car – and we all have odd rituals that we use to manage them. But what if we believed our own hype about these rituals and became cocksure, perhaps even harming ourselves?
Here is a concrete example. In the study of risk perception, people talk about "the licensing effect": when you take a vitamin pill, for example, you think you've done something healthy and wholesome, so you permit yourself to eat more chips and have a cigarette. It sounds like a nice idea, but a bit vague.
Two new experiments put flesh on these bones. Firstly, researchers took 74 undergraduates who were daily smokers, and divided them into two groups at random. The first group were given a dummy pill, a placebo, and were told just that: you're in the control group, taking a dummy pill, with no active ingredient. The other participants were in the vitamin pill group: you've been given a vitamin pill, they were told.
But in fact, the researchers had lied. Everyone in the study got the same dummy pill, with no active ingredient. Half of them thought they'd had a health-giving vitamin pill, because the intention was to see whether people's health behaviours change if they think they've had a nice, healthy vitamin pill.