Trust is a tricky business. On the one hand, it's a necessary condition _____(1) many worthwhile things: child care, friendships, etc. On the other hand, putting your _____(2), in the wrong place often carries a high _____(3).

_____(4), why do we trust at all? Well, because it feels good. _____(5) people place their trust in an individual or an institution, their brains release oxytocin, a hormone that _____(6) pleasurable feelings and triggers the herding instruct that prompts humans to _____(7) with one another. Scientists have found that exposure _____(8) this hormone puts us in a trusting _____(9): In a Swiss study, researchers sprayed oxytocin into the noses of half the subjects; those subjects were ready to lend significantly higher amounts of money to strangers than were their _____(10) who inhaled something else.

_____(11) for us, we also have a sixth sense for dishonesty that may _____(12) us. A Canadian study found that children as young as 14 months can differentiate _____(13) a credible person and a dishonest one. Sixty toddlers were each _____(14) to an adult tester holding a plastic container. The tester would ask, “What's in here?” before looking into the container, smiling, and exclaiming, “Wow!” Each subject was then invited to look _____ (15). Half of them found a toy; the other half _____ (16)the container was empty-and realized the tester had _____(17) them.

Among the children who had not been tricked, the majority were _____ (18) to cooperate with the tester in learning a new skill, demonstrating that they trusted his leadership. _____ (19), only five of the 30 children paired with the "_____(20)"tester participated in a follow-up activity.