Oxytocin, a hormone associated with lactation and social bonding, seems to make people more inclined to trust strangers with their cash. In a game in which 58 volunteers could invest money with anonymous trustees, economist Ernst Fehr of the University of Zurich and his colleagues dosed half the subjects with a whiff of oxytocin and the others with an inert placebo nose spray. After sniffing oxytocin, investors were roughly twice as likely to invest all their funds, and on average the oxytocin group put in nearly 20 percent more than placebo subjects. This effect was not seen when the trustee was replaced with a computer, revealing that oxytocin promotes social interaction instead of just making people more likely to take risks. In the June 2 Nature, the researchers suggest that this work could help alleviate social phobias, rather than assist mutual-fund agents.