My own life has in some ways been a decades-long tour of the sibling experience. I have full sibs, I have half-sibs, and for a time I had step-sibs.

Marriage is a lot of things - a source of love, security, the joy of children, but it's also an interpersonal battlefield, and it's not hard to see why: Take two disparate people, toss them together in often-confined quarters, add the stresses of money and kids - now lather, rinse, repeat for the rest of your natural life. What could go wrong?

All behavioral or mood disorders - including depression, OCD, ADHD and addiction - have some neurochemical components, but sufferers can still work to overcome them.

Narcissistic personalities usually do do better than you and me and the average person. We've always seen it in the office. The person who speaks up more in meetings, the person who's charismatic, who can sell an idea with more excitement and energy.

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.

A fishnet is made up of a lot more holes than strings, but you can't therefore argue that the net doesn't exist. Just ask the fish.

Science has yet to isolate the Godiva Chocolate or Prada gene, but that doesn't mean your weakness for pricey swag isn't woven into your DNA. According to a new study of identical twins, it's less TV ads or Labor Day sales that make you buy the things you do than the tastes and temperaments that are already part of you at birth.