insecurity impedes clear thinking,

and here's proof, my little ankle-biters (as Robin Williams would say).

More from Bringing Oxytocin into the room:

Perception, Mirror Neurons and Suggestibility

Several studies have shown that the brain is highly responsive to suggestion. In a series of remarkable experiments it has been shown that the performance of simple, seemingly unrelated tasks can be increased or decreased merely by placing a briefcase or sports equipment nearby, triggering unconscious associations with work or play.

In an interesting study, subjects were made happy or angry, then shown happy and angry faces and friendly and hostile interpersonal scenes in a stereoscope. Happy subjects perceived more happy faces and friendly interpersonal scenes while angry subjects perceived more angry faces and hostile interpersonal scenes.

In addition, it has been shown that relatively small favors or bits of good luck (like finding money in a coin telephone or getting an unexpected gift) induced positive emotion in people, and that these emotions increased the subjects’ inclination to sympathize or provide help.

On closer reading, it appears that the evidence he's gathered mostly has to do with men. Not so useful, unfortunately.