The licensing effect is the phenomenon whereby positive actions or decisions taken now increase negative or unethical decisions taken later. I’ve written about this previously, before I was aware of a general effect:

A Taiwanese study has provided us with a new instance of the licensing effect in action, this time with vitamin supplements. The study found that taking vitamin pills or dietary supplements for health protection increases unhealthy and risky behaviour.

Afterwards, compared with placebo participants, the participants who thought they’d taken a vitamin pill rated indulgent but harmful activities like casual sex and excessive drinking as more desirable; healthy activities like yoga as less desirable; and they were more likely to choose a free coupon for a buffet meal, as opposed to a free coupon for a healthy organic meal (these associations held even after controlling for participants’ usual intake of vitamin pills). […]

The vitamin-takers also felt more invulnerable than the placebo participants, as revealed by their agreement with statements like “Nothing can harm me”. Further analysis suggested that it was these feelings of invulnerability that mediated the association between taking a postulated vitamin pill and the unhealthy attitudes and decisions.

BusinessWeek also points out that this loop of benevolent and self-indulgent behaviour is plainly evident in the shopping habits of consumers… something that marketers know all about.

via @vaughanbell