Mix a bit of something that affects oxytocin levels into, say, a flu shot and suddenly, the public believes everything politicians, religious leaders, used car salesmen, Fox talk show hosts and others say without question. Now about that $5000 you owe me. Of course you owe it to me. Would I lie?

[Over] the past 10 years, oxytocin has come up in the world, and several researchers have begun making big claims about it. Now dubbed “the trust hormone,” oxytocin, researchers say, affects everything from our day-to-day life to how we feel about our government.

To understand the role that oxytocin plays in your own life, consider the experience of a small 9-year-old girl named Isabelle. [... who] has Williams syndrome, a rare genetic disorder with a number of symptoms. The children are often physically small and often have developmental delays. But also, kids and adults with Williams love people and are pathologically trusting: They literally have no social fear.

Researchers theorize that this is probably because of a problem with the area in their brain that regulates the manufacture and release of oxytocin. Somehow, the system in which oxytocin operates has been disrupted in a way that makes it essentially biologically impossible for kids like Isabelle to distrust.
[...]
Zak first got interested in trust more than a decade ago after co-authoring a study that looked at trust levels in different nations and their economic stability. The study found that the higher the level of trust, the better the economic status of the nation.

The work got Zak thinking more generally about different ways to manipulate trust. [...] Squirt oxytocin up the nose of a college kid, and he’s 80 percent more likely to distribute his own money to perfect strangers.

“We convert him, we capture his inner mind, we reshape him. We burn all evil and all illusion out of him; we bring him over to our side, not in appearance, but genuinely, heart and soul. We make him one of ourselves before we kill him. [...] We make the brain perfect before we blow it out.”
– George Orwell – 1984