Members of royal families are born into a world of indulgence and entitlement, and the princelings who grow up that way may never have to develop the emotional musculature that will allow them to show self-restraint.

The vexing thing about human behavior is that when we say we know we should do something, we really and truly do know it. It's hard to be 50 lbs. overweight or smoke a pack a day or feel miserable every moment you spend at work and not understand in a deep and primal way that change is in order - and that in some cases it could even save your life.

Narcissism is actually a clever guise adopted to mask its exact opposite, which is a deep well of self-loathing, a well of low self-esteem, rather than high self-esteem. This helps explain why narcissists are so sensitive to criticism, why narcissists tend to break into outrage if they're criticized, because their self-esteem is actually much more brittle than it seems, and once they're challenged, that mask falls apart.

In both children and adults, there can be a hard-to-deny link between a robust sense of hope and either work productivity or academic achievement.

The truth, of course, is that the only necessary and sufficient condition for human beings to murder one another is the simple fact of being human.

People with anxiety disorders such as OCD know that nothing can be more paralyzing than having too many options. Go to a store to buy a sweater, find four that you like and the odds are pretty good you'll stare and stare... and buy nothing at all.

Vaccines save lives; fear endangers them. It's a simple message parents need to keep hearing.