Jeffrey Kluger quotes:

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.

As the National Football League and other pro sports increasingly reckon with the early dementia, mental health issues, suicides and even criminal behavior of former players, the risk of what's known as chronic traumatic encephalopathy (CTE), is becoming clear.

Scarily, football helmets, which do a fine job of protecting against scalp laceration and skull fracture, do little to prevent concussions and may even exacerbate them, since even as the brain is rattling around inside the skull, the head is rattling around inside the helmet.

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?

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.

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.

As with real reading, the ability to comprehend subtlety and complexity comes only with time and a lot of experience. If you don't adequately acquire those skills, moving out into the real world of real people can actually become quite scary.

Every batch of sperm represents an opportunity for genetic typos - called de novo mutations - to be passed on. A 20-year-old man and woman will each pass on about 20 de novo mutations to a baby they conceive. By the time the couple is 40, a woman's total has remained at 20, while a man's has jumped to 65 - and it keeps climbing from there.

The brain sits snugly inside the skull, but it's not a completely flush fit - there is still a layer of fluid between bone and soft tissue that serves as a natural shock absorber. Some shocks, however, can't be absorbed, and when the head gets clobbered too hard, the brain can twist or torque or rattle around inside its skeletal casing.

I grew up in a suburb of Baltimore with an extremely high concentration of Jewish families - where the Levys and Cohens in the high school yearbook went on for pages, where I could count far more temples than I ever could churches. Anti-Semitism, in our cultural biodome, was mostly an abstract concept.

The death of anti-gay hate speech is no doubt being hastened by the head-spinning speed with which gays as a group - to say nothing of gay marriage - are becoming an unremarkable and even quite traditional parts of American life.

Humans have a fraught relationship with beasts. They are our companions and our chattel, our family members and our laborers, our household pets and our household pests. We love them and cage them, admire them and abuse them. And, of course, we cook and eat them.

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.

The best you can sometimes do is learn to take a breath, count to ten and simply accept that try as you might, no, your husband will never, ever learn not to drop a wet towel on the bed. That acceptance too counts as resolving a fight.

There are a lot of obstacles in the way of our understanding animal intelligence - not the least being that we can't even agree whether nonhuman species are conscious. We accept that chimps and dolphins experience awareness; we like to think dogs and cats do. But what about mice and newts? What about a fly? Is anything going on there at all?

There's a deep-freeze of sorts for all good intentions - a place that you store your plans to make changes in your life when you know you're not going to make them at all.

My family went through divorces and remarriages and the later, blended home - and then watched that home explode, too.

When you're your parents' one shot at a genetic legacy, you may get to attend all the best schools, wear all the best clothes and eat all the best foods - at least relative to children in multiple-sibling households. But you also wind up with an overweening sense of your own importance.

Toxins love to get you while you're young. Lead, mercury, secondhand smoke and sundry other environmental nasties do a lot more damage when tissue is immature, vulnerable and growing than when it's mature and comparatively fixed.

There are popular celebrities, there are unpopular celebrities and then there are the walking dead. You know the walking dead when you see them: they look like Mel Gibson, still striving for drunken charm in an L.A. County mug shot, after getting picked up on a DWI charge that included anti-semitic slurs directed at the police.

There are a lot of downsides to being male. We age faster and die younger. But give us this: we're lifetime baby-making machines. Women's reproductive abilities start to wane when they're as young as 35. Men? We're good to go pretty much till we're dead.

Habitual texters may not only cheat their existing relationships, they can also limit their ability to form future ones since they don't get to practice the art of interpreting nonverbal visual cues.

The mind of the polyglot is a very particular thing, and scientists are only beginning to look closely at how acquiring a second language influences learning, behavior and the very structure of the brain itself.

The golden child may be the oldest one, unless it's the youngest. It may be the toughest one, unless it's the most sensitive. It's not even necessary that Mom and Dad have the same favorite - and typically they don't.

As MBA professors endlessly tell their students, companies do best when they stick to what they do well. There's a reason Apple doesn't make blenders. There's a reason Haagen-Dazs doesn't sell meat. And there's a reason drug companies should focus on saving and improving lives - not jeopardizing them.

No one ever pretended that shopping for anything is a rational experience. If it were, would there be Fluffernutter? Laceless sneakers? Porkpie hats? Would the Chia Pet even exist?

Spare a thought for the poor introverts among us. In a world of party animals and glad-handers, they're the ones who stand by the punch bowl. In a world of mixers and pub crawls, they prefer to stay home with a book. Everywhere around them, cell phones ring and e-mails chime and they just want a little quiet.

Humans are crude linguists from the moment of birth - and perhaps even in the womb - to the extent at least that we can hear spoken sounds and begin to recognize different combinations of language sounds.

Everybody loves to spend money at least some of the time - because everybody loves the stuff you can buy with it. The key to the pleasure level of any transaction is the balance between the pain of the payment and the reward of the purchased object.

Psychopaths know the technical difference between right and wrong - which is one of the reasons their insanity pleas in criminal cases so rarely succeed; they just fail to act on that knowledge.

Suffering is always hard to quantify - especially when the pain is caused by as cruel a disease as Alzheimer's. Most illnesses attack the body; Alzheimer's destroys the mind - and in the process, annihilates the very self.

Narcissism falls along the axis of what psychologists call personality disorders, one of a group that includes antisocial, dependent, histrionic, avoidant and borderline personalities. But by most measures, narcissism is one of the worst, if only because the narcissists themselves are so clueless.

When it comes to raising civilized kids there are no hard rules, but there are two things on which most parents agree: Boys are generally wilder than girls, and adolescents are wilder than kids of any other age. If you've got an adolescent boy, you're in the sweet spot for trouble.

I was born in the U.S., my wife was born in Mexico and emigrated here when she was in college, and my daughters were born in New York City. That makes them passport-carrying, natural-born, eligible-to-run-for-president Americans. But they're also Mexicans and they like that just fine.

Athletes often start life at the opposite end of the wealth and prestige spectrum, but as soon as they exhibit an unusual talent for swinging a bat or sinking a free-throw they may find that the rules have been suspended for them. They are waved through school and into the pros, and incidents of bad behavior are overlooked or covered up.

Never mind what you've heard. Halle Berry was not the first black woman to win an Academy Award for Best Actress. She was actually the 74th white one. And never mind all this talk about America electing its first black President; Barack Obama is actually the 44th white man to hold the job.

Well, I think of the folks who are the climate deniers as the flat Earthers and the people who say the moon landings never happened.

There's a sort of sibling moratorium when you're establishing yourself as an adult. So much of your energy has to be focused on other things like work and kids. But when people become more settled, siblings tend to regroup because now you're building a new extended family.

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.

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

What makes spinal-cord injuries as devastating as they are is that everything about them plays out in absolutes: they are instantaneous, utterly disabling and horribly permanent.

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.

At the root of the shy temperament is a deep fear of social judgment, one so severe it can sometimes be crippling. Introverted people don't worry unduly about whether they'll be found wanting, they just find too much socializing exhausting and would prefer either to be alone or in the company of a select few people.

There's only one thing harder than living in a home with an adolescent - and that's being an adolescent. The moodiness, the volatility, the wholesale lack of impulse control, all would be close to clinical conditions if they occurred at another point in life. In adolescence, they're just part of the behavioral portfolio.

What people fear most about tragedy is its randomness - a taxi cab jumps the curb and hits a pedestrian, a gun misfires and kills a bystander. Better to have some rational cause and effect between incident and injury. And if cause and effect aren't possible, better that there at least be some reward for all the suffering.

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.

There are a lot of ways to make people not like you, but one of the most powerful - if least fair - is to be really, really successful. Nobody resents the guy who just lost his job. But the guy whose Internet start-up made him a billionaire at 25? That's a whole different kettle of envy.

It's not mere extremism that makes folks at the fringes so troubling; it's extremism wedded to false beliefs. Humans have long been dupes, easily gulled by rumors and flat-out lies.

There's no one place a virus goes to die - but that doesn't make its demise any less a public health victory. Throughout human history, viral diseases have had their way with us, and for just as long, we have hunted them down and done our best to wipe them out.

Certainly, people can get along without siblings. Single children do, and there are people who have irreparably estranged relationships with their siblings who live full and satisfying lives, but to have siblings and not make the most of that resource is squandering one of the greatest interpersonal resources you'll ever have.

Becoming food savvy is one thing, but it's amazing how fast savvy turns to snooty, and snooty leaves you preparing three-hour meals that break your budget and that the kids won't even eat.

The families of many athletes - incensed at the sports leagues and hoping to make games safer overall - are increasingly making the brains of players who die prematurely and suspiciously available for study. Some athletes are even making the bequest themselves.

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.

There aren't a lot of ironclad rules of family life, but here's one: No matter how much your parents deny it - and here's betting they deny it a lot - they have a favorite child. And if you're a parent, so do you.

We're learning how important it is both to preserve sibling relationships if they work and repair them if they're broken. We're also learning a lot about nonliteral siblings - stepsiblings, half-siblings - and the surprising power they can have.

A close family member once offered his opinion that I exhibit the phone manners of a goat, then promptly withdrew the charge - out of fairness to goats.

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.

There's plenty to read about keeping your sanity while raising children, but it's all common-sense stuff about task division and taking breaks and the relentlessly repeated magic of date night with your spouse. What's missing is some 'tude.

Some of the most rewarding times my brothers and I have are when all of us get together, and we can see what we've been building genetically and culturally.

Sisters have ways of socializing brothers into the mysteries of girls. Brothers have ways of socializing sisters into the puzzle that is boys.

There's no such thing as downtime for your brain.

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.

A mere ape in our world may be a scholar in its own, and the low life of any beast may be a source of deep satisfaction for the beast itself.

You do not want to talk to me on the phone. How do I know? Because I don't want to talk to you on the phone. Nothing personal, I just can't stand the thing. I find it intrusive and somehow presumptuous. It sounds off insolently whenever it chooses and expects me to drop whatever I'm doing and, well, engage. With others!

There's a reason narcissists don't learn from mistakes and that's because they never get past the first step which is admitting that they made one. It's always an assistant's fault, an adviser's fault, a lawyer's fault. Ask them to account for a mistake any other way and they'll say, 'what mistake?

When an organization starts hemorrhaging talent, CEOs and boards of directors want to know why. If the boss gets blamed for the brain drain and is ultimately removed, it means relief for the employees still there and ex post facto vengeance for the former ones.

From the time we're born, our brothers and sisters are our collaborators and coconspirators, our role models and our cautionary tales,

Marketers have long known that a name can make all the difference when you're trying to move the merch. The kiwifruit was once the Chinese gooseberry, after all - at least until the produce peddlers wised up - and the Chilean sea bass was once the singularly unappetizing Patagonian toothfish.

The best thing about science is that hard, empirical answers are always there if you look hard enough. The best thing about religion is that the very absence of that certainty is what requires - and gives rise to - deep feelings of faith.

When we're awake, cortisol can fragment memories - one reason eyewitness crime scene accounts are so unreliable. But at night that very fragmentation allows creative recombinations of ideas.

A jellyfish is little more than a pulsating bell, a tassel of trailing tentacles and a single digestive opening through which it both eats and excretes - as regrettable an example of economy of design as ever was.

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

There may be no more-radioactive term in the English language than what we now almost always refer to as the 'n-word' - itself a coy means of linguistic sidestepping that is a sign of how perilous it is to utter the thing in full, even in conversations about language.

Older siblings get more total-immersion mentoring with their parents before younger siblings come along. As a result, they get an IQ and linguistic advantage because they are the exclusive focus of their parents' attention.

Part-black generally means all-black in Americans' minds. Just as part-Asian or part-Hispanic or part-anything-else usually puts individuals in those minority-groups' camps.

Since narcissism is fueled by a greater need to be admired than to be liked, psychologists might use that fact as a therapeutic lever - stressing to patients that being known as a narcissist will actually cause them to lose the respect and social status they crave.

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.

More and more NFL players have been willing their bodies to science so that their brains can be studied even if they die of other causes.

If you're an older sibling and you have a younger sibling who needs mentoring or is afraid of the dark, you develop nurturing and empathic skills that you wouldn't otherwise have.

Operating-room errors hold a special terror for patients, if only because they seem like the most avoidable kind of complications. The occasional horror stories of patients who have the wrong leg removed or the wrong knee replaced generate the most headlines, as do tales of patients whose identities are mixed up entirely.

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.

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.

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.

Spending $1 for a brand new house would feel very, very good. Spending $1,000 for a ham sandwich would feel very, very bad. Spending $19,000 for a small family car would feel, well, more or less right. But as with physical pain, fiscal pain can depend on the individual, and everyone has a different threshold.

Confidence quickly curdles into arrogance; smarts turn to smugness, charm turns to smarm.

Older fatherhood isn't all bad: testosterone rates drop about 1% per year as men age, making them less reactive and more patient, and a professionally established middle-aged man is likely to have more time and money to devote to his kids than a twenty-something who's just getting started.

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

It's one of the worst-kept secrets of family life that all parents have a preferred son or daughter, and the rules for acknowledging it are the same everywhere: The favored kids recognize their status and keep quiet about it - the better to preserve the good thing they've got going and to keep their siblings off their back.

Introverts listen better, they assess risks more carefully, they can be wiser managers. It's not for nothing that the Silicon Valley billionaires are so often the retiring types.

Kids whose puberty begins too soon face not just psychological risks, but physical ones too, with an increased likelihood of cancer, as well as skeletal changes that could prevent them from attaining their full adult height.

Is there anything sadder than the foods of the 1950s? Canned, frozen, packaged concoctions, served up by the plateful, three meals per day, in an era in which the supermarket was king, the farmer's market was, well, for farmers, and the word 'locavore' sounded vaguely like a mythical beast.

A cockroach likely has no less brainpower than a butterfly, but we're quicker to deny it consciousness because it's a species we dislike.

We are all born with an innate understanding of interpersonal equity - the idea that if you lend me your rake today, I'll respond in kind when you come to borrow my shovel tomorrow. Or nearly all of us are born with that. Psychopaths aren't.

Paul McCartney had a baby when he was 61; Rod Stewart was 66; Rupert Murdoch was a stunning 72. Not only does that mean they'll have less stamina than the average dad, that means they'll, well, check out a lot sooner too.

When our culture shifts, it tends to overcorrect, throwing out everything associated with an era we've moved past, rather than saving what was good and combining it with what is new.

A child gets vaccinated and soon after, autism symptoms emerge. The apparent cause-and-effect is understandable but erroneous - more a coincidence of the calendar and childhood developmental stages than anything else, as repeated and exhaustive studies have shown.

For years now, Chinese parents and teachers have lamented what's known as the 'xiao huangdi' - or little emperor - phenomenon, a generation of pampered and entitled children who believe they sit at the center of the social universe because that's exactly how they've been treated.

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.

Odds are you know some narcissists. Odds are they're smart, confident and articulate. They make you laugh, they make you think; the first time you met, they probably charmed the pants off of you - perhaps even literally. The odds are also that that spell didn't last.

There's a universe inside your head - a place of pictures and passions, of songs and sorrows. It's everything you are - and it's an utter mystery.

Why are some people born with a fire in the belly, while others need something to get their pilot light lit?

Ambition is an expensive impulse, one that requires an enormous investment of emotional capital. Like any investment, it can pay off in countless different kinds of coin.

Sadoway does more than entertain; he gives you a glimpse into the future of energy.

When you learn conflict-resolution skills in the playroom, you then practice them on the playground, and that in turn stays with you. If you have a combative sibling or a physically intimidating, older sibling, you learn a lot about how to deal with situations like that later in life. If you're an older sibling and you have a younger sibling who needs mentoring or is afraid of the dark, you develop nurturing and empathic skills that you wouldn't otherwise have.

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.

Even the best computer in the world has no idea that it exists. You do. No one knows what creates that ineffable awareness that we're here...

We pride ourselves on being the only species that understands the concept of risk, yet we have a confounding habit of worrying about mere possibilities while ignoring probabilities, building barricades against perceived dangers while leaving ourselves exposed to real ones.

Photography is about freezing a moment in time; McGinley's is about freezing a stage in a lifetime.

Kids are anarchy writ large.

Learning to speak was the most remarkable thing you ever did.

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.