A little self-mastery can improve the quality of your life as well as the quantity. If you are a man, it can preserve your marriage, since a strong predictor of marital stability is the husband’s ability to control his impulses. And if you’re a student, it can lead to higher lifelong earnings, since you are likely to do better—and go further—in school. Studies of teenagers have found that self-discipline is a much better predictor of academic performance than IQ—and may account for the superior grades of girls, who display more of it. Self-control is associated with more education, less violence, lower alcohol and drug abuse, higher earnings, and an optimistic outlook—but only moderate optimism. One study of 997 Catholic Church personnel found that a high score on a test of conscientiousness—defined as “a tendency to control impulses and be goal-directed”—predicted an 89 percent lower risk of Alzheimer’s disease than the risk among low scorers, even after allowing for age, gender, and education level.

The range of actions—and therefore outcomes—that are subject to volition is much larger than we have been led to believe. If we hold ourselves responsible for our behavior—none of which is entirely voluntary—we are more likely to consciously direct our actions rather than succumbing to impulse. The magnificent result might be for more of us, even in some small way, to take charge of our own destiny. Doing this requires a kind of faith, but only in our own power to choose. It requires imagination, so that we can visualize the future that our sacrifices might produce. And it requires cleverness, for creating methods to promote the kind of deeds we prefer. In the absence of these three things we too easily become our own worst enemy.

The moral dimensions of self-control inevitably lead us to political questions. If you believe your life is largely the result of your own discipline and decisions, you’re going to feel very differently about taxes, regulations, and redistribution than if you believe your life is largely the sum of your genes and your environment—factors irretrievably beyond your control. In general, conservatives seem to believe in people’s ability to control themselves more strongly than liberals do, except when the behavior is bad for women, minorities, or the planet, in which case the two sides trade places. Either way, the troubles many of us have with willpower raise big questions about how far government should go to try to save us from ourselves. Both sides claim to advocate lots of freedom, yet both support government intervention to keep people from exercising it, whether by limiting divorce or abortion (those conservative bête noires) or piling on taxes and regulations (the perennial choices of liberals).

To get a better handle on this problem, let’s think for a moment about desires. Like people, they fall fairly easily into two broad categories: those that we like and those that we don’t. What I mean by selfcontrol is deciding which of your desires you really want to espouse and then upholding them against the challenges of the competing desires that you like less. This distinction—between any old desire that we may have and the desires we actually want for ourselves—is crucial. We’ll call the former first-order desires, to describe the grab bag of appetites and longings that seem to beset us without conscious intervention. The others—those essential desires that you actually prefer—we’ll call second-order desires.

To the philosopher Harry Frankfurt, who enjoyed a short-lived celebrity outside the world of academic philosophy when his brief book On Bullshit climbed the best-seller lists, those second-order desires are the things that make you a person. Frankfurt’s notion is that while lots of creatures can deliberate, what sets Homo sapiens apart is the “structure” of our will—the way we can select or even cause our own motivation, or will our own will. Your humanity, in a sense, derives from having preferred preferences, and you are free to the extent that you are able to make your actions conform to the desires you want for yourself.

So smoking is a major self-control problem. How major? Well, the World Health Organization has estimated that global warming claims 150,000 lives annually, a toll that could double by 2030. The very same agency estimates that, by the very same year, tobacco will kill 8 million annually around the world, or roughly twenty-seven times the number of deaths attributable to climate change. The comparison raises a provocative question: Which is a bigger public health challenge, global warming or self-control?

Our sorry diet is causing biological changes aside from obesity. Lots of sugary foods can reduce insulin sensitivity over time, leading to diabetes. Rats exposed to very high-fat meals lose sensitivity to the hormones that normally signal satiation—and so they keep eating. Supercaloric diets (and the extra estrogen produced by the resulting additional fat cells) appear to be the main culprits in driving the average age of female puberty in this country down to eleven years old, with many reaching that stage even younger. Our high-carbohydrate, high-calorie diet has also been implicated in delaying brain maturity by a year or two. Full brain maturity may now take until age nineteen or twenty because too many calories lowers brain-derived neurotrophic factor, a protein important for the brain’s development. (And delaying brain maturity means postponing the day when we achieve our fullest capacity for self-control.)

Type 2 diabetes is already reaching alarming proportions. Type 2, which represents more than 90 percent of all diabetes cases, is usually found in overweight adults—and it’s booming. There were 5.6 million Americans with diabetes in 1980. By 2007 the figure had more than quadrupled to nearly 24 million, with another 57 million believed to be prediabetic. Eleven percent of adult Americans have the disease, which has grown right along with our body weight, but in this arena, too, the Chinese are proving competitive. Thanks to increasing affluence, China now leads the world in diabetics, with 92 million. Its adult rate of one in ten comes perilously close to ours.

Perhaps the very best evidence that suicide is impulsive—that it’s a self-control problem—comes from the United Kingdom, in the convenient natural experiment offered by the nation’s shift to heating with natural gas. England for years had relied on cheap and plentiful coal gas, which is rich in carbon monoxide and thus can asphyxiate an unlucky householder in minutes if the doors and windows are closed. By the late 1950s, it accounted for nearly half of U.K. suicides. In 1963, the poet Sylvia Plath killed herself in her London home just this way—by turning on the gas and sticking her head in the oven. But by the early 1970s, when the changeover to natural gas was virtually complete, the English suicide rate had dropped by nearly a third and has stayed down ever since, indicating that people didn’t simply turn to other means of doing themselves in. The coal gas evidently was too convenient, and unhappy people with a passing fancy to end it all could do the deed impulsively, without going anywhere or buying anything. In matters of self-control, as we shall see again and again, speed kills. But a little friction really can save lives.

These Odyssean techniques for constraining our own behavior—paying men to keep us out of opium dens, giving away the guns we fear we’ll turn on ourselves—are known in the self-control racket as forms of precommitment, because we use them to constrain ourselves in advance against the foreseeable strength of some later desires. Precommitment is about limiting our own choices while we’re safely distant from the temptations we suspect we can’t otherwise handle. Why should we need any of this clanking self-control paraphernalia, with which the future haunts the present like some rattling ghost afflicting Scrooge? The answer is in the bedeviling problem known to self-control cognoscenti as time inconsistency, which describes the frustrating way our preferences change along with our state of desire. Think of Coleridge’s conflicting views of opium: When the poet was clean and calm, he hired men to keep him that way, on the basis of a strong preference for sobriety. But when he had a hankering, he demanded that the men stand clear, because, crucially, his preferences had reversed.

Deadlines seem to benefit everyone. Dan Ariely has tried letting his students write short papers over the course of a semester with no deadlines (beyond term end), with deadlines of their choosing, or with deadlines that he imposed. Ariely found that students got better grades when given hard and fast deadlines spaced out across the semester. Students with no deadlines, who presumably had the most time and flexibility to work on all their papers, actually performed worst, while the performance of students who were allowed to set their own deadlines was only middling. The problem was that some students in the self-imposed deadline group underestimated their tendency to procrastinate—sound familiar?—and so set deadlines that weren’t well spaced, leading to rushed, poorly written papers.

Advances in farming, food science, transportation, refrigeration, and the like have made food in this country wondrously cheap, as we have seen. (A single datapoint illustrates the change: from 1970 to 2005, the proportion of after-tax income Americans spent on food fell from 14 percent to just 10 percent—and forty cents of every food dollar went for eating out, the USDA says.) One result is that we are mostly better fed than we used to be. Another is that we are mostly fat.

It almost goes without saying that television is an inducer of selfcontrol problems—particularly with respect to watching TV. Despite the Internet, Americans still average around five hours of TV daily, and there are good reasons for wanting to cut down. People who watch more TV tend to be less happy, for example, even after taking account of differences in income, education, and the like. Perhaps this is because the heavy TV watchers, research has shown, feel less safe, trust others less, are more materialistic, and less satisfied with their lives. They are also more likely to be fat. Many of these people, in fact, wish they watched less, meaning they have a self-control problem, and many of them know it. In Gallup polls during the 1990s, 40 percent of adults and 70 percent of teens said they spent too much time watching, while other surveys found that about 10 percent of adults considered themselves addicted to

No more diabolical means of procrastination than the Internet has ever been created, since its delights and distractions come to us through the same machine we use for work.

In fairness, prosperity is often a plus on the self-control front. In general, the affluent are better at deferring gratification; people’s talents in this arena may even be the cause of their affluence rather than its consequence. Perhaps that’s why well-to-do Americans, for whom food is relatively cheapest, are paradoxically least likely to be overweight. But sudden access to a lot of money makes for problems, as we’ve seen from the many lottery winners who’ve run off the rails over the years.

Would you be surprised to learn that America’s high breakup rate might have something to do with self-control? For there are really two states of matrimony in America—one for those with education, and a much less stable one for those without. (Imagine them as the Denmark and Iraq of nuptials.) The divorce rate among college-educated women—probably the Americans who would score highest in any test of self-control—is much lower than it is among women without undergraduate degrees. And education is associated with better impulse control.

“We are what we repeatedly do,” Will Durant wrote in summarizing Aristotle on this score. “Excellence, then, is not an act but a habit.”

Mischel’s plan raises a crucial question. If self-control is so important for kids, can it be taught? There is every reason to believe that it can. Nobody seems to think it’s 100 percent hereditary, after all. Mischel contends that good parenting plays a large role—even in everyday matters like not snacking before meals. And researchers have already found some value in programs aimed at teaching children “executive functions,” which is psychological jargon for self-control. Adele Diamond evaluated a fascinating program called Tools of the Mind, developed by psychologists Deborah Leong and Elena Bodrova. The program asked students to plot their play intentions in writing, and their days were filled with various other games and activities designed to promote planning, focus, and delay of gratification. In a study of 147 kids roughly divided between those in Tools of the Mind and those not, Diamond found that after two years the program participants did quite a bit better on tests of executive function—suggesting they really did learn some self-control.

What’s interesting about Loewenstein’s findings here is the suggestion that the self is so deeply divided between hot or cold that in one state we are a stranger to ourselves in the other. “These kinds of states,” he says, “have the ability to change us so profoundly that we’re more different from ourselves in different states than we are from another person.”

We live in a world of such supernormal stimuli today. In affluent countries, supernormally appealing rewards—heavily sweetened lattes, unnaturally large breast implants, mesmerizing computer games—appeal to our evolutionary instincts with captivating force far beyond that which we evolved to withstand. The relatively low cost of such refined products as sugar, cocaine, and even gasoline means that the only thing between us and our instincts is a thin membrane of willpower, or an even thinner membrane of mindfulness. The problem, as Mark Leary attests, “is not that our modern lives are worse than those of prehistoric humans but, rather, that our lives require a far greater amount of self-control. As a result, we sometimes push our efforts to control ourselves past the self’s ability to respond . . . The result is not only occasional failures of self-regulation, some of which are disastrous, but also a chronically low level of self-control strength.”

Recent research (which will come as no surprise to exasperated parents) has demonstrated that teenagers have frontal lobes that aren’t ready for prime time, either, as is perhaps evident from their driving record: in the United States, mile for mile, teens are four times more likely to have an accident than adult drivers, and auto accidents are the leading cause of teenage deaths. Teenagers are different from you and me, and the differences are more than skin-deep. Aside from acne, one big difference is that teens don’t have a fully formed prefrontal cortex. From birth, the human brain is growing and changing to meet the demands of a complex environment. We are born with a plethora of synapses, which are the things that connect nerve cells in the brain. In fact, we’re born with more than we need. Some synapses transmit excitatory information, which increases the likelihood that the receiving neuron will send an impulse to another neuron. But other synapses are inhibitory, and these reduce the likelihood that the receiving neuron will fire. Our extra synapses get pruned as we grow up, and in this process it’s mostly excitatory synapses that are eliminated—with the result that the balance shifts over time toward inhibitory circuits, leading us away from the action bias associated with impetuous youth. There is probably some poignant trade-off here; as William Wordsworth (along with Natalie Wood) reminds us, “nothing can bring back the hour of splendour in the grass.”

Hormones, neurotransmitters, and many other potentially relevant biological factors are at least partly genetic as well, as are some other self-control-related characteristics, such as novelty-seeking and, especially, intelligence. The ability to defer gratification is strongly associated with intelligence, and Yale psychologist Jeremy Gray, who has studied this connection, says intelligence is 50 to 80 percent hereditary (although some psychologists say the proportion is lower). “Some portion of delay discounting is heritable,” Gray told me in an interview, referring to how strongly people prefer larger-later to sooner-smaller rewards. “I’d be amazed if it turned out to be different.”

Although both sexes are slaves to their hormones, there is no getting around the fact that women have more self-control than men. In every culture, men commit vastly more violence, which is associated with impulsivity. Women the world over are more religious, and being religious is associated with the ability to defer gratification. Men’s impulse control is a leading predictor of divorce. Females of every age are more prone to shame and guilt. Boys are much more likely than girls to be diagnosed with attention deficit disorder and hyperactivity. Textile mill and apparel entrepreneurs across time and cultures—from nineteenth-century England to modern China—have preferred female employees, often fresh off the farm, for their diligence and docility. Males take more risks. Females of every age get better grades in school but score about the same on IQ and achievement tests, suggesting the difference may be self-discipline. The list goes on and on. The bottom line: your level of self-control is influenced by whether you have a Y chromosome.

Basically this law says that animals (including us) acting freely will spend their time doing things in direct proportion to the relative value they get from each. Herrnstein derived this law working with those Harvard pigeons; he discovered that, when offered two different objects to peck, the birds pecked them in proportion to the rate of reward delivered by each. Varying the quantity of reward—a little grain—had the same effect. And most interesting of all, preference was proportional to the inverse of delay. In other words, the later the reward, the less the birds liked it. And the less they would peck. What the matching law did was to express mathematically the experimental evidence that organisms discount future rewards. Even pigeons, apparently, will weigh larger, later rewards against smaller, sooner ones and, if the larger reward is not sufficiently larger, pick the smaller, sooner one—as if they have some instinct that reminds them that a bird in hand is worth two in the bush. And since self-control is about deciding between now and later (perhaps even infinitely later, a period otherwise known as “never”), the matching law provided something like a formula for self-control.

Price also affects consumption, even when the price isn’t as high as early death. The economists Philip Cook and George Tauchen found that higher liquor taxes significantly reduce the incidence of cirrhosis of the liver, a reliable proxy for chronic heavy drinking. The main argument against legalizing substances such as marijuana and cocaine—that more people will abuse them—implies that laws and penalties make a difference in whether they are abused and therefore that addiction is far from invariably compulsory.

For this brief history we can thank Piers Steel, a University of Calgary psychologist who has made a specialty of the subject, and who reports that prevalence appears to be growing, at least according to some researchers. Studying procrastination is not always easy. Students of the literature evidently have to cope with endless pranks, including a fake history that cites the authors Stilton and Edam for a report on the use of cheese in a study of procrastination in mice. Steel, however, takes the subject seriously and has even developed an impressive-looking formula that supposedly captures such factors as the desirability of a task and a person’s sensitivity to delay. Steel also has a procrastination Web site—but then again, aren’t they all?—which offers an eighty-one-question quiz to help you measure your procrastinating tendencies, although one would think merely taking such a quiz would answer any doubts. (Google it if you must.)

Procrastination is a classic self-control failure because procrastinators almost always have a strong second-order preference not to procrastinate. The job won’t go away, after all, and putting it off won’t make it any easier. Procrastination is also associated with other selfcontrol shortcomings. In studies, procrastinators score low on selfcontrol questionnaires and also score low for the specific personality trait known to psychologists as conscientiousness. Expressed in terms the Greeks would have used, procrastination is an example of the type of akrasia Aristotle called astheneia, or sheer weakness, in that we want to get to the task at hand, we know we should, and if we could utter an incantation to make it so, we would. But somehow we just can’t muster the strength of will.

So we seem to think procrastination will make us feel better. Yet the cure is worse than the disease, because putting off the job usually makes us even more anxious and depressed. The existence of procrastination is further evidence that self-destructive behaviors can be voluntary. Think of yourself at work: You freely decide to check your e-mail, seducing yourself with the balm of distraction for an instant’s relief. You’re not leaving your desk, after all; you’re still at your keyboard! Yet how willingly you jump through any escape hatch that presents itself, and how much better it feels just now to be reading an article in the Financial Times or looking for bargains on eBay. The great psychologist Alfred Adler, who gave us the inferiority complex, saw neurosis “not as unconscious repression but as a deliberate ruse whereby one evades some overwhelming task,” and by this standard procrastination is neurotic indeed.

Procrastination is a ruse. We know what’s really going on, but we want badly to be fooled. For instance, people chronically underestimate the amount of time and effort a task will take even though they know better. “Scientists and writers, for example, are notoriously prone to underestimate the time required to complete a project,” according to the psychologists Daniel Kahneman and Amos Tversky, “even when they have considerable experience of past failures to live up to planned schedules.” Kahneman and Tversky called this the planning fallacy, and it crops up all over the place, particularly when we’re facing an onerous task; repeated experiments have shown that people consistently predict they can get a job done faster than the time it ultimately takes. This excessive optimism isn’t just American; it’s been demonstrated in Japan and Canada as well. Some people even suggest that the benefits of underestimating the time required by a task—and therefore putting off work on it—can outweigh the costs associated with poor planning. Self-deception may be necessary lest the true magnitude of the job scare us away altogether. And

We also deceive ourselves with the diverting tasks we perform instead of the job we’re so busily putting off. Household chores suddenly become pressing, for example. When asked how to write a novel, Hemingway supposedly told people that first you clean the refrigerator. Or we linger at the first stages of a task: one of my sons, who is supposed to practice the saxophone nightly, can spend an amazingly long time unpacking his instrument and moistening the reed before he plays a note. Delays of this kind, carried to extremes, might qualify as pathology; “primary obsessional slowness” is said to occur when people with obsessive-compulsive disorder take a really, really long time to do almost anything, including getting dressed or preparing to go out.

Giving in to procrastination feels bad even while it feels good, like eating too many potato chips. And it’s exhausting; it takes a lot of concentration sometimes to avoid doing what you know you’re going to have to do sooner or later (and perhaps with greater difficulty). Attention has to be kept off the business that should be at hand, and attention control of any kind takes energy. What a shame to waste so much of it fending off the only thing—tackling the avoided work—that could put an end to the situation.

On the contrary, America’s aristocracy of self-control seems ideally adapted to the world in which we find ourselves, blast their steely backbones. It’s as if they got the news ahead of the rest of us—no doubt by waking up earlier—that self-control may well be the most important personal trait of the twenty-first century.

The Anglo-Israeli economist Avner Offer has suggested that this is precisely why the public sector is so large in Western democracies, consuming roughly 30 to 55 percent of gross domestic product. In his view, people are sophisticated enough to know that the package of benefits provided by the state—a package they have to pay for—will do more for their well-being than they could accomplish if they were left to spend their money on their own. Taxes, in this way of thinking, are just a costly precommitment device by means of which the electorate makes itself forgo unsatisfying profligacy in favor of insurance against age, illness, and destitution.

So how can each of us be our own godfather? The answer is to shuck the naïveté of the untutored in favor of a more sophisticated approach to ourselves and our intentions. That means, first, relying as little as possible on willpower in the face of temptation. It’s much better, like Odysseus, to row right past the cattle of the sun god than to count on controlling the hunger that could lead to a fatal barbecue. It also means acknowledging how much we are influenced by our surroundings—and taking command of our environment so that it influences us in ways we prefer.

Ellis and the Stoics both saw emotions as largely voluntary states to which we can assent or not, as we see fit. Ellis, who wrote books on dealing with alcohol, anger, procrastination, and mood regulation, stressed changing the way you think about your problems. Self-deception, “catastrophizing,” and other harmful mental activities are to be rooted out and subjected, along with other bad habits, to the merciless scrutiny of the prefrontal cortex. The idea is to acquire accurate knowledge about yourself and your environment and put it to use. Cognitive behavioral therapy is even something you can practice on yourself. Is it rational to eat just because something is bothering you? If not, then find a way to cut it out.

Don’t be naïve: your environment acts on you in ways you can’t begin to realize. So why not structure your environment to get the desired responses? All you have to do is make the default conditions of your life—the things that happen as a result of inertia—consistent with your second-order preferences. Better things are likely to happen, and you won’t waste cognitive resources on a lot of unnecessary choices. Decide in advance to row right past the cattle of the sun god. One of the best areas for investment in environment control is attention management. Remove distractions from your desk. If you want to spend less time on the Internet, use software to block access—or at the very least, turn off e-mail and disconnect chat programs for a while. Unplug the phone, resort to earplugs the way Odysseus’s sailors did—anything to remove unwanted diversions. If you can’t remove distractions and temptations, try changing the way you think about them. Avoid focusing on their most seductive properties and think about who you really want to be. With regard to your home environment, don’t buy the things you need to avoid. Shop when you aren’t hungry. Order online, far away from the sights and smells that are so tempting in a store. Take your credit cards out of your wallet and leave them at home in a drawer. Imagine about how much you have to earn pretax to pay for whatever it is you’re thinking of buying.

Another useful way of using your environment to bolster self-command is to make sure you have some exposure to nature. It pains me to write this, since the only nature that interests me is human, yet studies demonstrate that urban life, with its stress and anonymity, poses a threat to self-control. Cities are stimulating but also cognitively demanding; even a short walk in a city can undermine attention and memory. Children with attention deficit disorder suffer fewer symptoms in a more natural setting. A study of inner-city girls found that a view of green space accounted for 20 percent of variance in self-discipline scores. In a public housing project in Chicago, women whose apartments overlooked a grassy courtyard were better able to focus their attention and cope with major life challenges than…

If you’re serious about living up to your second-order preferences—and you’ve taken the trouble to formulate some, as people often do when they make New Year’s resolutions—then the truly radical approach is to treat yourself like one of B. F. Skinner’s pigeons. People often do so instinctively by promising themselves a certain reward—opening the good wine, buying a new dress, taking a vacation in Hawaii—when a certain goal is met. But self-rewards can be tricky without appointing someone else to bestow or withhold the prize. If you don’t mind treating yourself like a lab rat—and let’s face it, we’re not all that different—then friends and family members can be a big help. If I had told my wife not to let me take a drink in…

If you want to make a difficult but enduring change, announce it (to yourself and others) well in advance; an engagement period is always useful in getting one’s intended to the altar. It’s not by chance that the military allows enlistees a period of time between signing and induction. One study of charitable giving found that it rose when a delay was permitted between pledging and giving. Another study found…

What habits are is sticky. Bad ones, which seem to travel in packs, are the hardest to break because they are built from our most instinctual urges. Good ones are to be cherished; self-command can be achieved, Aristotle tell us, when “obedience to reason becomes habitual.” William James devoted an entire chapter to habit in his monumental The Principles of Psychology, observing (with his own ardent italics) that “the great thing, then, in all education, is to make our nervous system our ally instead of our enemy. It is to fund and capitalize our acquisitions, and live at ease upon the interest of the fund. For this we must make automatic and habitual, as early as possible, as many useful actions as we can, and guard against the growing into ways that are likely to be disadvantageous to us, as we should guard against the plague.”