The book’s central metaphor, borrowed and adapted from Hindu philosophy, is the elephant and the rider. The rider is the conscious, reasoning mind — the part that reads philosophy, sets goals, makes resolutions, and believes it’s in charge. The elephant is everything else: the vast, ancient, powerful unconscious system of emotion, intuition, habit, and embodied response that actually drives most human behavior. The rider can suggest, guide, train, and occasionally redirect the elephant. The rider cannot override the elephant by force of will, though, and is far more dependent on the elephant’s cooperation than it likes to believe.
Not original to Haidt — he acknowledges his debt to the Upanishads and Plato’s charioteer — but he develops it with unusual care and applies it with extraordinary range. Understanding that you have an elephant — that your emotional, intuitive, embodied nature isn’t a broken version of your rational nature but the primary engine of your life — is, Haidt argues, the beginning of wisdom about both happiness and ethics.
Ten Great Ideas
Haidt structures the book around ten “Great Ideas” — ancient insights about human happiness he evaluates through the lens of contemporary psychology. Not all of them survive the scrutiny, but most do, often in modified forms, and the evaluation process is itself illuminating about what ancient wisdom got right and where it fell short of accounting for human complexity.
The first great idea concerns the divided self — the observation, found in virtually every wisdom tradition, that humans are in conflict with themselves. Paul’s complaint that he does what he doesn’t want to do and fails to do what he wants. The Freudian division between conscious and unconscious. The Buddhist recognition that the self isn’t a unified agent. All of it pointing at the same phenomenon modern psychology has now documented rigorously: the human mind is not one thing. It’s a collection of semi-independent systems, often with incompatible goals, operating at different speeds and with different levels of conscious access.
The rider-elephant framework captures this with particular clarity. The rider evolved later and operates more slowly. Good at analysis, planning, and language — but limited bandwidth, tires easily. The elephant is fast, powerful, tireless. It handles emotion, habit, social intuition, threat detection, and the vast majority of moment-to-moment processing that keeps you alive and functioning. The rider isn’t useless — it can learn, plan, redirect — but it cannot win a direct confrontation with the elephant. Anyone who’s tried to willpower their way out of a bad habit or an emotional reaction already knows this.
The practical implication Haidt draws from this first idea: happiness requires working with the elephant, not against it. Meditation — which trains attention and creates space between stimulus and response — works by changing the elephant. Cognitive behavioral therapy works by changing the automatic thoughts and interpretations the elephant generates. Habit formation works by training the elephant so the desired behavior becomes its default.
Pure reasoning and willpower, working against the elephant, rarely succeed and rarely stick.
The Adaptation Principle and the Pursuit of Pleasures
Haidt’s second great idea concerns what he calls “the adaptation principle” — closely related to what Daniel Gilbert calls hedonic adaptation. The ancient Stoics understood this clearly: external circumstances don’t determine happiness as reliably or as durably as we expect, because we adapt to circumstances and return to our emotional baseline. Epictetus, born into slavery and later freed, arrived at essentially the same conclusion through direct experience: what we control — our judgments, desires, responses — matters far more to our wellbeing than what we don’t control — our circumstances, other people’s behavior, fortune.
Modern psychology has confirmed this with remarkable precision. The hedonic treadmill — achieving a desired goal, experiencing a burst of happiness, adapting to the new level, returning to baseline while setting a new, higher goal — is one of the most replicated findings in happiness research. It explains why people in wealthy countries aren’t substantially happier than people in moderately comfortable ones, why material progress over the past century hasn’t produced corresponding increases in self-reported happiness, and why people reliably overestimate how much their happiness depends on their circumstances.
But Haidt, following the research carefully, identifies an important limit to the adaptation principle. Not everything adapts equally. Some things — noise, commuting, chronic pain, social comparison — adapt poorly or not at all. Others — meaningful work, deep relationships, spiritual practice, engagement with beauty — adapt slowly or not at all, because they keep generating new value. The practical lesson isn’t the Stoic one of becoming indifferent to circumstances. It’s more detailed: invest heavily in the things that resist adaptation and lightly in the things that don’t.
This leads Haidt to a qualified defense of what he calls “pleasures” — the simple, immediate satisfactions of good food, physical comfort, beauty, play, sensory delight. Eastern philosophy, and some strands of Western philosophy, have sometimes dismissed these as trivial or distracting. Haidt argues that’s a mistake. Pleasures aren’t the foundation of a good life, but they’re real goods — they contribute to wellbeing, generate positive emotion that broadens and builds cognitive resources, and are often more readily available than the bigger goods of meaning and love. Ignoring pleasures in pursuit of transcendence is a form of spiritual overclaiming.
The Elephant Moves: Reciprocity, Gossip, and the Social Animal
Haidt spends considerable time on the social dimensions of happiness, drawing on evolutionary psychology to explain features of human nature wisdom traditions observed without fully understanding. Two are particularly important: reciprocity and what he calls “the moral emotions.”
Reciprocity — the powerful human tendency to return benefits for benefits and harm for harm — is among the most deeply wired features of the social elephant. It evolved because cooperation requires reliable partners, and reliable partners are distinguished by their responsiveness to favors and defection. The reciprocity system operates fast and below conscious awareness: gratitude toward people who help us, resentment toward people who exploit us, often before we’ve consciously assessed the situation.
This automatic reciprocity makes human cooperation possible at scales that would otherwise be impossible. It also creates some of the most reliable sources of social friction — the sense of being taken advantage of, the slow accumulation of resentment when a relationship feels unbalanced, the difficulty of accepting favors graciously when you can’t immediately reciprocate. Understanding these feelings as the elephant’s automatic responses, not considered judgments, helps you respond to them more skillfully — and helps explain why reasoning people out of them rarely works.
Gossip, which Haidt treats with more seriousness than its reputation warrants, is the primary mechanism through which social groups enforce norms. By sharing information about who behaved well and who behaved badly, gossipers build the reputation system that makes large-scale cooperation possible. Not pretty, easily abused, but genuinely functional — and the negative emotions associated with being gossiped about (shame, humiliation, social exclusion) are powerful motivators of prosocial behavior. The wisdom here isn’t to transcend gossip but to understand its function and participate in it with more awareness of its power and its costs.
The Faults of Others and the Hypocrisy of the Self
One of Haidt’s most practically important chapters concerns what he calls “the faults of others” — the universal human tendency to see other people’s flaws clearly while remaining largely blind to our own equivalent flaws. Not hypocrisy exactly, because hypocrites know they’re doing wrong and do it anyway. More fundamental: we simply have systematically better access to information about other people’s behavior than to information about our own motivations and biases.
The elephant, Haidt argues, is a lawyer, not a scientist. It doesn’t evaluate evidence impartially in pursuit of truth. It evaluates evidence in pursuit of a desired conclusion — typically, that we ourselves are virtuous, that our group is right, that our enemies are wrong. The rider, rather than correcting for this bias, typically serves as the elephant’s advocate: constructing post-hoc rationalizations for whatever the elephant has already decided, then presenting those rationalizations to the world as reasoned conclusions.
This insight — that moral reasoning is more often rationalization than genuine deliberation — is uncomfortable but important. It means that when we feel certain of our moral positions, that certainty is often the product of motivated reasoning rather than careful analysis. It means the people we disagree with are typically not evil or stupid — they’re simply running their own lawyer-elephants in a different direction, defending their own group’s conclusions as vigorously as we defend ours.
The practical wisdom Haidt draws from this echoes various ancient traditions: work on yourself before judging others, cultivate genuine humility about the reliability of your own moral perceptions, approach disagreement with at least some curiosity about how reasonable people could arrive at opposite conclusions. Not relativism — Haidt believes some moral positions are better supported than others — but an antidote to the self-righteous certainty that makes productive conversation impossible.
Changing Your Mind: Meditation, Therapy, and Medication
If the elephant is the primary driver of behavior and the rider can’t force change through willpower, how does genuine psychological change happen? Haidt’s answer draws on both ancient wisdom and contemporary research, converging on a small set of interventions that work by changing the elephant rather than overriding it.
Meditation — specifically mindfulness meditation — works by training attention and creating what Buddhist teachers call “a gap” between stimulus and response. With enough practice, even strong emotional reactions lose their automatic grip. The meditator learns to observe rising anger or anxiety as an event in consciousness rather than a command to act. This doesn’t eliminate the emotion — the elephant still generates it — but it changes the relationship between the emotion and the behavior that follows. The rider gains genuine use.
Cognitive behavioral therapy works by identifying and modifying the automatic thought patterns the elephant generates in response to certain situations. These patterns — catastrophizing, personalizing, all-or-nothing thinking — are the elephant’s habitual interpretations, laid down by experience and reinforced by repetition. CBT doesn’t attack them directly with reasoning; it trains the system to generate different automatic responses through structured practice. It works on the elephant’s level, through repetition and rehearsal, rather than the rider’s level, through argument.
And medication — particularly antidepressants — can work by changing the biochemical environment the elephant operates in. Haidt takes a detailed position here: he doesn’t advocate medication as a first resort or a substitute for psychological growth, but he resists the purist position that pharmacological intervention represents cheating or weakness. If the elephant is partly shaped by neurochemistry, and that neurochemistry can be adjusted to reduce suffering without eliminating the person’s capacity for growth and meaning, then such adjustment isn’t categorically different from the other forms of elephant-training wisdom traditions have always endorsed.
The Happiness Formula: Setpoint, Conditions, and Voluntary Activities
Drawing on Sonja Lyubomirsky’s research, Haidt describes what he calls the “happiness formula”: H = S + C + V. Happiness (H) is the sum of a biological set point (S), life conditions (C), and voluntary activities (V).
The set point S is the baseline level of happiness each person tends to return to following life events — the equilibrium of the hedonic treadmill. Research on twins, and on people whose circumstances change dramatically, suggests roughly 50% of variance in happiness comes from genetic factors that shape the set point. Some people are born with nervous systems that lean positive; others lean toward anxiety or dysphoria. Not destiny — the set point can shift, and environments can express genetic predispositions more or less strongly — but a real constraint any honest account of happiness has to acknowledge.
Life conditions C — income, health, marital status, physical safety, freedom — matter more than adaptation skeptics sometimes suggest, but less than intuition tells us. The most important conditions are those people adapt to most slowly: chronic noise, long commutes, lack of autonomy, repeated social comparison with people who are better off. Haidt’s advice: change the conditions that resist adaptation (get out of a noisy environment, shorten your commute if at all possible, reduce involuntary social comparison with the rich and successful) and accept that other conditions will adapt more quickly than you expect.
Voluntary activities V are where the most practical use lies. Because they’re self-chosen and varied, they resist adaptation more than fixed circumstances. They’re also directly under our control in a way the set point and many life conditions aren’t. The key insight, backed by a substantial body of research: activities that are intrinsically motivated, that involve absorption and flow, that connect us to others, and that contribute to something larger than ourselves tend to deliver the most durable happiness — far more than activities oriented toward consuming pleasures or acquiring status.
Why Meaning Matters More Than Happiness
Haidt makes a distinction many happiness researchers minimize: happiness as pleasurable feeling versus meaning as the sense that life matters, that one’s actions connect to something larger than oneself, that one’s existence has significance. These often coincide, but not always. Parents of young children report lower moment-to-moment happiness than non-parents but higher sense of meaning. People in demanding creative or professional work often report mixed emotions but high levels of meaning. People who’ve survived serious adversity often describe their lives as more meaningful, if not always more pleasant, than before the adversity.
The ancient wisdom traditions Haidt surveys were generally more interested in meaning than in happiness in the hedonic sense. The Stoics wanted to live virtuously, not pleasurably. The Buddhists wanted freedom from craving and suffering, not a surplus of positive emotion. Confucianism oriented life toward social relationships and role fulfillment. None of these traditions would recognize contemporary positive psychology’s focus on maximizing positive affect as a coherent account of the good life.
Haidt’s synthesis is that both matter — but interact. Meaning generates positive emotion over time, even when it involves present difficulty. And positive emotion, which Barbara Fredrickson’s research has shown to “broaden and build” cognitive and social resources, tends to make people better at finding and sustaining meaningful activities. The relationship is bidirectional and mutually reinforcing. The wise course isn’t pursuing one at the expense of the other but investing in both while understanding how they feed each other.
Love and Attachment: The Need for Others
Haidt devotes careful attention to human relationships and the role love and attachment play in wellbeing. Drawing on attachment theory (Bowlby and Ainsworth), evolutionary psychology, and research on social connection, he argues human beings are fundamentally social animals whose wellbeing depends not just on the presence of others but on the quality of their attachments to them.
The research is unambiguous: social connection is one of the strongest predictors of subjective wellbeing, health, and longevity. Lonely people are less healthy, less happy, and die sooner than well-connected people. The quality of close relationships — characterized by responsiveness, trust, genuine interest in each other’s wellbeing — predicts life satisfaction more reliably than income, health, or achievement.
Haidt distinguishes between two kinds of love wisdom traditions have often conflated: eros, the passionate, romantic love of early relationships, intense and powerful but biologically designed to be temporary; and what he calls “companionate love,” or, drawing on the Greek tradition, philia — the calmer, deeper, more durable love of long-term partnership, friendship, and kinship. Both are real and valuable. But eros isn’t a sustainable foundation for lifelong relationships. It’s the beginning of a process, not the end state. People who expect the electric intensity of early romantic love to persist indefinitely in long-term relationships are setting themselves up for disappointment, because they’re expecting the elephant to stay permanently aroused — which is not how the elephant works.
The wisdom here is ancient: genuine love requires time, shared experience, vulnerability, and the kind of mutual responsiveness that can only develop through the ordinary business of living together. The contemporary romantic ideal — a perfect partner who meets all your needs and makes you feel permanently special — is a recipe for chronic disappointment, because it sets an expectation no actual human relationship can meet. The more realistic, more achievable goal is a partnership that’s good enough, deeply comfortable, and provides the secure base from which both people can engage with the rest of their lives.
Adversity and Post-Traumatic Growth
One of the book’s most important chapters concerns what Haidt calls “the adversity hypothesis” — the ancient idea, found in Stoic philosophy, in Buddhism, in virtually every religious tradition, that adversity and suffering can be genuinely good for human development. Not that suffering is desirable in itself — the Stoics didn’t seek suffering — but that the human capacity for growth is often activated most powerfully by difficulty, loss, and failure.
This idea seemed merely consolatory until psychologists Richard Tedeschi and Lawrence Calhoun began systematically documenting what they called “post-traumatic growth” — people not merely recovering from trauma but emerging from it with stronger relationships, greater personal strength, new possibilities they hadn’t previously considered, a deeper appreciation for life, and sometimes a transformed spiritual or philosophical understanding. Not universal, not automatic. But real, and more common than the trauma literature had previously suggested, since it had focused almost exclusively on PTSD and other negative sequelae.
Haidt’s interpretation draws on the elephant-rider model. Traumatic experiences can force a confrontation with the fundamental assumptions that have organized one’s life — assumptions about safety, about one’s own capabilities, about what matters most. When those assumptions shatter under an event that can’t be ignored or rationalized away, the mind has to rebuild. And the rebuilt structure is often stronger, more flexible, more realistically calibrated than the original. The assumptions that survive the confrontation get genuinely tested; the new ones get built from the materials of actual experience rather than inherited expectations.
The practical implication isn’t to seek adversity — masochistic and unnecessary, since adversity tends to arrive on its own schedule — but to approach difficulty understanding that the growth it can generate is real, documented, and valuable. The suffering isn’t pretend. But in most cases, it isn’t the final chapter either.
Transcendence, Elevation, and the Sacred
Haidt’s most distinctive contribution, and the one that most sets The Happiness Hypothesis apart from typical positive psychology texts, is his serious treatment of transcendence, elevation, and the sacred. Most happiness research either ignores religion and spirituality or treats them as tools for generating positive emotion. Haidt takes a more respectful position: these dimensions of human experience aren’t simply happiness-delivery mechanisms but responses to genuine aspects of human existence that secular psychology is poorly equipped to address.
He describes a phenomenon he calls “elevation” — the emotion triggered by witnessing acts of great moral beauty, courage, or compassion. Not the same as happiness, admiration, or pride. A distinctive feeling, often accompanied by warmth in the chest, a sense of the goodness of humanity, and a motivation to become better oneself. Haidt and his colleagues have documented it across cultures and connected it to the vagal system — the parasympathetic nervous system that mediates social bonding and trust.
Elevation suggests human beings are not only pleasure-seeking but meaning-seeking in a specifically moral sense — oriented toward goodness, toward transcending narrow self-interest, toward participating in something larger and more beautiful than individual existence. The religious and philosophical traditions that have cultivated this orientation — through ritual, story, practice, community — have been doing something real. They’ve been training the elephant to respond to moral beauty with the motivation to embody it.
The happiness that comes from such motivation — from the sense of participating in something genuinely good and genuinely larger than oneself — is different in kind from hedonic pleasure and different from the life satisfaction of achieved goals. It’s what Haidt, drawing on Emile Durkheim, calls the happiness of being part of something bigger: the “hive switch,” the capacity for self-transcendence evolution built into the human social animal because groups that could act as one outperformed groups of pure individuals.
The Final Synthesis: Happiness Comes From Between
Haidt’s final synthesis is elegant and important. Happiness, he argues, comes from between — from the relationship between the self and others, between the self and work, between the self and something larger than the self. Not found within (through meditation, self-sufficiency, or detachment from the world) or without (through the acquisition of goods, status, or pleasurable experiences). Ancient philosophy was right to suspect external goods and right to emphasize inner work. But wrong to identify inner peace with detachment and self-sufficiency.
The strongest and most consistent predictors of human happiness are deeply relational: the quality of close personal relationships, the sense that one’s work contributes something of value, the feeling of belonging to a community that shares one’s values, the experience of love — given and received — in its various forms. None of this can be achieved in isolation. It requires other people, shared projects, and ongoing engagement with the world’s complexity and beauty and difficulty.
This isn’t a comfortable synthesis for contemporary Western individualism, which frames the good life primarily in terms of personal autonomy, individual achievement, and freedom from constraint. Haidt’s research and his reading of the ancient wisdom traditions both suggest that framing, however appealing to the rider, is incomplete — that the elephant is a social animal whose deepest satisfactions live in connection, contribution, and the sense of belonging to something that matters.
Resilience, Adversity, and the Elephant’s Wisdom
For anyone building resilience — the capacity to face difficulty without being permanently diminished by it — The Happiness Hypothesis offers several of the more practically useful insights available in the happiness literature. The adversity hypothesis, backed by solid research on post-traumatic growth, provides an evidence-based case for the ancient intuition that suffering can be generative. The elephant-rider model provides a framework for understanding why willpower and positive thinking so often fail to produce lasting change — and points toward the interventions (meditation, therapy, habit formation) that actually work by changing the system rather than overriding it.
The insight about meaning versus happiness is particularly important for resilience. People who’ve organized their lives around meaning — around a cause, a calling, a set of relationships, a commitment to something larger than themselves — show greater resilience in the face of adversity than people whose primary orientation is hedonic. Not because meaningful lives involve less suffering, but because they provide a framework within which suffering can be made sense of and integrated rather than simply endured.
And Haidt’s synthesis — that happiness comes from between, from the quality of our connections to others and to something larger — suggests the resilience resources we most need are rarely fully internal. The stoic ideal of the self-sufficient sage, impervious to fortune, is psychologically unrealistic. The human animal is built for connection, and the strongest form of resilience isn’t the solitary endurance of a hero but the sustained engagement of a person embedded in relationships, commitments, and communities that make the work of rebuilding possible.
The elephant knows this, even when the rider has forgotten. The task is to listen.
The Divided Self in Practice
Understanding the divided self isn’t merely an intellectual exercise. It has immediate, practical consequences for how we approach the challenge of living well. Most self-improvement efforts fail, Haidt observes, because they’re designed by the rider and implemented against the resistance of the elephant. We make resolutions we don’t keep. We identify habits we want to change and then find ourselves, weeks later, enacting the old habits again with a mixture of guilt and bewilderment. We set intentions and fail to follow through. The rider blames weakness, moral failure, or lack of discipline. But the actual problem is that the elephant was never persuaded.
The rider’s tools — reasoning, resolve, moral argument — are genuinely useful but limited in scope. They work best for decisions that can be made once and then implemented through changed circumstances: taking the junk food out of the house, signing up for a class, committing to a partner, moving to a new city. These decisions put the elephant in a different environment where it can’t pursue the old habits as easily. The environment has changed; the elephant’s path has been altered. Far more effective than trying to override the elephant’s preferences through sheer willpower on every individual occasion.
The wisdom traditions that work most reliably on the elephant — Buddhism, Stoicism in its practical forms, the monastic traditions of Christianity and Judaism — all understood this. They built elaborate structures of ritual, community, practice, and environmental design that changed what the elephant encountered and what responses became habitual. They didn’t rely on riders deciding to be virtuous and then somehow compelling their elephants to comply. They built systems that trained elephants over years of practice until the desired responses became second nature.
For the contemporary person, this suggests a different approach to personal change. Rather than asking “How do I force myself to do this?” ask “How do I design my environment and habits so this becomes what my elephant naturally does?” Rather than relying on motivation and inspiration — rider experiences, often short-lived — invest in the infrastructure of habits, relationships, and commitments that make the desired behavior easier and the undesired behavior harder. Work with the grain of human nature rather than against it.
The Cross-Level Coherence of Flourishing
One of Haidt’s most resonant concepts is what he calls “cross-level coherence” — the alignment between different levels of one’s personality: the biological level of temperament and physical health, the psychological level of values, beliefs, and identity, and the social level of relationships, roles, and community belonging. Flourishing, Haidt argues, isn’t simply the presence of positive emotion or the achievement of goals. It’s the felt sense of everything fitting together — of being who you’re supposed to be, doing what you’re meant to do, in the company of the right people, in pursuit of the right ends.
This cross-level coherence is hard to achieve and hard to describe, but most people have experienced at least glimpses of it — moments when work, relationship, purpose, and self felt simultaneously engaged and aligned. Not mystical experiences. What happens when the rider and the elephant are pointing in the same direction, when the social self is embedded in meaningful community, and when the activities of daily life resonate with the deepest commitments of the person performing them.
The happiness that results from such coherence differs from, and outlasts, the happiness that comes from acquiring a desired object or achieving a particular goal. Not a peak experience but a sustainable condition — a baseline of engagement and meaning the ordinary texture of life draws its color from. The kind of happiness the ancient wisdom traditions were actually aiming at: not excitement or pleasure, but the deep rightness of a life lived in accordance with one’s nature and one’s values.
Haidt doesn’t pretend this state is easily achieved or universally available. Poverty, injustice, illness, and social exclusion can all prevent cross-level coherence by making it impossible to align one’s activities with one’s deepest values. The wellbeing research consistently shows material and social conditions matter — not infinitely, not as much as intuition suggests, but genuinely. A society that fails to provide its members with adequate security, meaningful work, and genuine community will produce unhappy people no matter how much positive psychology they’re exposed to.
But within the range of conditions that allow for basic security, differences in human flourishing are largely explained by the alignment or misalignment of the person with their activities, relationships, and purposes. And that alignment is something that can be cultivated — through the patient training of the elephant, through the careful selection of commitments and communities, and through the ongoing work of clarifying what one actually values as opposed to what one has been told to value.
Ancient Wisdom, Modern Validation
The most intellectually satisfying aspect of The Happiness Hypothesis is watching Haidt work through the ancient wisdom and find — repeatedly, with genuine surprise — that the sages were onto something real. The Stoic insight about the limits of external goods is confirmed by adaptation research. The Buddhist insight about the self’s divided nature is confirmed by cognitive neuroscience. The ancient observation that adversity builds character is confirmed by post-traumatic growth research. The universal religious emphasis on community and belonging is confirmed by the social connection literature.
This doesn’t mean the ancients got everything right. Their cosmologies are often scientifically untenable. Their ethics sometimes reflected the prejudices of their cultures rather than universal human values. Their prescriptions for psychological change sometimes aimed at states — radical detachment, complete self-transcendence — that are neither achievable nor desirable for most people living ordinary lives.
But the practical, behavioral core of the great wisdom traditions — invest in relationships, work on your reactions rather than your circumstances, seek meaning in contribution and connection, treat others as you wish to be treated, cultivate the capacity for gratitude and forgiveness — holds up remarkably well under empirical scrutiny. Not arbitrary cultural prescriptions. The accumulated practical knowledge of centuries of human observation about what works and what doesn’t, refined through the natural selection of traditions that produced wellbeing and the disappearance of traditions that didn’t.
Haidt’s contribution is making this case rigorously — with citations, effect sizes, and honest acknowledgments of where the evidence is mixed or absent. The result is a book that deserves reading by anyone who takes seriously both the question of how to live well and the question of what we actually know about human flourishing. One of the few popular psychology books that deserves to be read slowly, argued with, and returned to.
Related: A World Without Email Summary
Related: The Rise of Superman Summary
FROM THE LIBRARY ›
References
Editorial StandardsCorrectionsMedical DisclaimerAbout Our ContentAffiliate DisclosureSite Map