Tamerlan Tsarnaev is telling no tales. The older of the two brothers who committed the Boston Marathon bombings was likely the one who planned the attack, but when he died in a shootout with police just days after the blasts, his thoughts and motivations vanished with him.

Overspending is as certain a part of the holiday season as overeating. But pushing away from both the table and the cash register at least a little bit sooner can make the post-holiday hangover hurt a little bit less.

Jellyfish serve as a model for bioengineers for the same reason yeast were once so valuable to geneticists: they're simple to deconstruct.

Narcissism, like the other personality disorders, is a condition that's known as ego-syntonic. In other words, the paranoid person really does believe that people are after him, and the narcissist really does believe that he or she is better than or more entitled than other people, and truly doesn't see why that's not the case.

It's far too much to say that effective hoping is the only - or even the biggest - part of what it takes to succeed. If 14% of business productivity can be attributed to hope, that means 86% is dependent on raw talent, fickle business cycles, the quality of the product you're selling, and often pure, dumb luck.

Credit or debit cards, for starters, are nothing short of shoppers' Novocain. Even in the age of digital purchases and virtual money, we still attach a special value to dirty paper with pictures of presidents on it. Handing some of that to a cashier simply hurts more than handing over a little sliver of plastic.

Identical twins are ideal lab specimens for studying the difference between learned and inherited traits since they come from the womb preloaded with matching genetic operating systems. Any meaningful differences in their behaviors or personalities are thus likely to have been acquired, not innate.