Person holding ecstasy pills

The street drug ecstasy elicits euphoria and feelings of closeness to others. Credit: dpa picture alliance/Alamy

Neuroscience

The party drug that helps to patch over betrayal

Ecstasy can promote cooperation after one partner is double-crossed by another.

The recreational drug nicknamed ecstasy might make individuals more willing to cooperate with those who have recently betrayed them.

In a study of social interactions, Anthony Gabay at King’s College London and his colleagues asked 20 men to play a strategy game against computerized players. Independently of each other, players and their digital partners chose during a series of trials to either cooperate with or compete against each other.

Mutual cooperation garnered players more points than did mutual competition. But players earned the most points when they ‘betrayed’ their partners by choosing to compete while the partner chose to cooperate. A ‘betrayed’ partner earned the lowest possible number of points. The men played the game after taking MDMA — ecstasy’s active ingredient — or after taking a placebo.

When the men were ‘betrayed’ by a generally trustworthy computerized partner, they tended to choose competition rather than cooperation in subsequent trials. Compared with their performance while taking a placebo, players on MDMA overcame this effect more quickly and thus returned to cooperation sooner.