Jeffrey Kluger — American Writer

Jeffrey Kluger is a senior writer at Time Magazine and author of nine books on various topics, such as The Narcissist Next Door; Splendid Solution: Jonas Salk and the Conquest of Polio; The Sibling Effect; and Lost Moon: The Perilous Voyage of Apollo 13. The latter work was the basis for Ron Howard's film Apollo 13. He is also the author of two books for young adults: Nacky Patcher and the Curse of the Dry-Land Boats and Freedom Stone... (wikipedia)

The mind and the body are inextricably entwined, and rarely are their inseparability clearer than when we're under some kind of mental pressure. The moment we start trying to learn a new skill, make a decision or otherwise think on our feet, our nervous system reacts - with accelerated pulse rate, increased respiration, even sweating.
Indeed, the best way to think of willpower is not as some shapeless behavioral trait but as a sort of psychic muscle, one that can atrophy or grow stronger depending on how it's used.
It's a deep and all but certain truth about narcissistic personalities that to meet them is to love them, but to know them well is to find them unbearable. Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.
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.
Your parents leave you too soon and your kids and spouse come along late, but your siblings know you when you are in your most inchoate form.