The Science of Happiness



An search of the word “happiness” yields over 20,000 results, with book titles detailing the “Happiness Hypothesis,” the “Happiness Advantage,” the “Art of Happiness,” or even the “How of Happiness.”  According to a 2005 study conducted by the U.S. Centers for Disease Control and Prevention (CDC), 2.4 billion drugs were prescribed that year -- 118 million were antidepressants, making them the most common class of drugs prescribed in the U.S. Millions of people devoted their time and energy to chasing “happiness” and even more time attempting to define and quantify it.  Even the Founding Fathers of the United States believed that all shared an equal right to the “pursuit of happiness.”  So what exactly is this elusive “happiness” and why does it have such a hold on humanity?

What is happiness?

In everyday terms, “happiness” is often used synonymously with “contentment,” “joy,” “pleasure,” and “satisfaction.”  Often categorized as a “state of mind,” happiness remains largely undefined in colloquial terms.

Famed psychologist Sigmund Freud proposed one of many early theories on happiness and how it could be achieved.  He argued that the main goal of mankind is to attain happiness.  Freud’s pleasure principle stated that happiness could be achieved through having all of one’s needs met, but even then, one was not a peak happiness.  The best form of happiness, Freud proposed, could only be achieved when one was faced with extreme suffering -- starvation homelessness, and other despondent circumstances.  The realization that this suffering is possible would cause one to appreciate his own circumstances and consider himself “happy” because he had escaped this potential suffering, lending credence to the cliche, “you don’t know what you have until it’s gone.”

For many years this theory persisted -- that happiness was merely the absence of suffering or misery.  Dr. Nancy Etcoff, PhD, a psychologist from the Harvard Medical School and the Harvard Mind/Brain/Behavior Initiative, says that this Freudian way of thinking largely “reflects the anatomy of the human emotion system.”  We are equipped with a positive and negative emotion system.  However, the negative emotion system is much more sensitive than the positive emotion system.  For example, humans are able to distinguish between “sweet” and “bitter,” reacting positively to sweet flavors, and negatively to bitter ones.  However, our ability to distinguish bitter tastes is much sharper than our ability to detect sweet ones: we can detect bitterness at one part per two million, whereas we can detect sweetness at only one part per two hundred.  The extreme sensitivity to negative things explains why people are generally more disappointed by losing than they are pleased by winning, and why one negative comment can take at least five times as many positive comments to counterbalance it.

However, the science of happiness is beginning to move away from this Freudian idea of “doom and gloom” happiness, in which a person’s emotions fall somewhere on a linear spectrum between “happy” and “sad.”  By Freud’s logic, the less “sad” you get, the more “happy” you become, but as reason and experience may tell you, this is often not the case.  When you become less sad, you simply become “less sad” -- happiness does not always follow.  For years, psychotherapy focused primarily on making people less sad, returning them to a “zero” from a “negative,” completely leaving out the possibility of boosting happiness above the “zero” level.  Dr. Etcoff contends that happiness is increasingly being viewed as a parallel system between positive and negative emotions, where each system needs to be addressed separately for one to truly be “happy.”

The field of positive psychology focuses on the “beyond zero” aspect of mental health.  Created in response to the bias of classical psychotherapy to treatment of mental illness as opposed to promotion of mental wellness, positive psychology has gained much support in recent years.  Dr.  Martin Seligman, PhD, Director of the Positive Psychology Center at the University of Pennsylvania, selected positive psychology as the theme for his term as president of the American Psychological Association (APA) in 1998, ushering in a new era of psychology.  Much of the knowledge we have about the science of happiness stems from studies that were initiated under the umbrella of positive psychology, helping to scientifically ground an often-ambiguous subject.  


What Makes Us Happy?

In our perpetual quest for happiness, we often find ourselves thinking in terms of what we lack and how this impedes our ability to be happy.  “If I was richer/more successful/in a relationship -- then I would be happy.”  You might be surprised to learn just how wrong you are.  

the claim: happiness is genetic.

In a highly publicized article published in Psychological Science in 1996, researchers from the University of Minnesota found that approximately 80% of one’s happiness is based on one’s genes.  This data, based on tracking identical twins, demonstrated that these genetically identical individuals had happiness levels that were highly correlated with each other, even when the twins were raised separately in different households.  This research left us with the disparaging thought that, as Dr. David Lykken, PhD, put it, “perhaps trying to be happier is as futile as trying to be taller.”  However, recent research has sparked new hope.  A 2009 study published in the Proceedings of the National Academy of Sciences analyzed data from 60,000 adults and found that in contrast to the previous study, only 50% of one’s happiness was that it was genetically determined, 10 -15% is based on life circumstances, such as sex, income, health, and marital status, and 40% is based on one’s own actions taken to intentionally increase happiness.  This means that a significant portion of happiness can be controlled by what we choose to do.  

Conclusion: A certain amount of happiness is indeed genetic, but the rest is left for us to shape.

The claim: happiness is being rich.

“Money can’t buy you happiness.”  Though we’ve all heard this old adage, it cannot be denied that sometimes it seems that a billion dollars could be the solution to all our woes.  However, according to a 2010 study published in the Proceedings of the National Academy of Sciences, we might not need a billion dollars -- we just need $75,000.  The study conducted by economist Dr. Angus Deaton, PhD, and Nobel Laureate Dr. Daniel Kahneman, PhD, analyzed more than 450,000 responses to a daily survey that asked participants how they felt the previous day, if they were living the best life possible for them, and what their annual income was.  Surprisingly, lower

income itself did not cause people sadness, but rather made people feel more burdened by the problems they were already experiencing.  For example, among divorced individuals earning less than $1000/month, 51% reported feeling sad the previous day.  In contrast, only 24% of divorced individuals earning more than $3000/month reported these same feelings of sadness.  However, once an individual’s annual income reached $75,000, the increase in happiness seen with increased income disappeared.  Interestingly, the study found that an individual’s disposition and life circumstances had a greater influence on his happiness than money did after an individual was earning more than $75,000 per year.  In general, the study concluded that 85% of Americans, regardless of their annual income, feel happy each day.  As Dr. Lykken puts it, “people who go to work in their overalls and on the bus are just as happy, on average as those in suits who drive to work in their own Mercedes.”  In fact, Dr. Edwards Diener, PhD commonly referred to as “Dr. Happiness,” concluded from a 1980s survey of Forbes 100 wealthiest Americans that even the extremely rich are only slightly happier than the average American.

Conclusion:  Money can buy you satisfaction-- to a point.  After the $75,000 threshold, more money may not do you more good, happiness wise.

the claim: happiness is having a social network

It may seem like common knowledge that family and friends make someone happier, but in a 2008 study published in the British Medical Journal, these sentiments were tested and validated by scientific methods.  The study followed approximately 5,000 individuals for 20 years in the Framingham Heart Study, an ongoing study of cardiovascular health in individuals from Framingham, Massachusetts.  When happiness was analyzed, researchers found that clusters of happy and unhappy people were clearly visible amongst the surveyed individuals, and furthermore, an individual’s happiness extended up to three degrees of separation, such that the friend of one’s friend’s friend was impacted.  Thus, people who were surrounded by many happy people were more likely to become happy in the future, demonstrating that an individual's happiness is dependent on the happiness of those they are connected to, such as friends and family.  

Conclusion: Happiness is infectious.  Are you willing to spread the “disease”?

the claim: happiness is being young

Some people assume that older we get, the less happy we will be.  However, a recent survey by the CDC found that people between the ages of 20 to 24 report feeling sad for an average of 3.4 days a month, compared to just 2.3 days for people ages 65 to 74.  Additionally a 2010 study published in the Proceedings of the National Academy of Science demonstrated that people generally showed an increase in their psychological well being after the age of 50.  Stress and anger generally decline after the early 20s, worry was elevated through middle age and then began to decline, and sadness remained consistent for all age groups.  Due to the general decrease in all of these negative factors, the researchers concluded that there was a post midlife increase in general well being and happiness.

Conclusion: Happiness does not always come with youth, and in fact, may be elevated with old age.


Chemical Happiness

On a biological level, happiness manifests itself in the brain through a number of different chemicals:

Dopamine: the motivator

The brain’s reward system is largely governed by the chemical dopamine, which is a neurotransmitter released in the brain, meaning that it transmits signals from a neuron to a target cell across a synapse.  Dopamine is commonly associated with feelings of enjoyment and motivation, which cause a person to continually seek out behaviors that stimulate this dopamine release.  In 1954, James Olds and Peter Milner published a paper in the Journal of Comparative and Physiological Psychology describing their now famous experiment in which they electrically stimulated the nucleus accumbens (a collection of neurons in the brain that received input from dopaminergic neurons) of a rat’s brain.  Rats pushed a lever in the testing apparatus that sent a stimulus through an electrode connected to the rat’s brain.  What they saw was that rats that received the electrical stimulation repeatedly returned to the lever to continue pressing it, disregarding any desire to eat, sleep, or copulate.  This discovery highlighted the brain’s reward system, which causes of dopamine in certain regions of the brain, triggering feelings of motivation and desire.  Dopamine release gives the stimulus incentive salience, transforming it into something that requires attention, induces desire, and must be obtained or sought out.  In this situation, the electric stimulus produced by pressing the lever triggered dopamine release, giving the lever incentive salience, and causing the rats to “need” to continuously push the lever.  Olds and Milner referred to this feedback loop as positive reinforcement -- pushing the lever caused dopamine release, which created a desire in the rat to push the lever again and again.

Serotonin: the happiness “hormone”

Serotonin, the happiness “hormone,” is actually a neurotransmitter derived from tryptophan an amino acid found in many protein-based foods, but most famously in turkey.  Serotonin deficiencies have been associated with symptoms of depression, aggression, and anxiety.  A 2006 paper published in Science described depression-like states in mice that lack a protein important for serotonin signaling throughout the brain.  For all these reasons, drugs that alter serotonin levels, such as selective serotonin reuptake inhibitors (SSRIs), are some of the most commonly prescribed drugs used to treat depression and anxiety disorders.

Endorphins: the relievers

Endorphins, commonly associated with the phenomenon known as “runner’s high,” are released by the pituitary gland and hypothalamus during exercise, pain,excitement, love, and orgasm.  Endorphins mimic opiates in their function and are known to produce analgesia, or pain relief, and a general sense of well-being,  A 2008 study published in Cerebral Cortex documents runner’s high, the state of euphoria the results from long-distance running and allows runners to continue running, despite pain.  Using positron emission tomography (PET) scanning, researchers were able to visualize endorphin release in the brain before and after athletes went running, and found that release of endorphins corresponded with feelings of exhilaration and runner’s high.  

Melatonin: the balancer

Melatonin is the hormone responsible for regulating your circadian rhythm, or daily cycle of sleep and wake, day and night.  As a result, disruption of melatonin levels causes tiredness and lethargy or alternatively, insomnia.  Melatonin was also reported in a 2006 paper published in the Proceedings of the National Academy of Science to relieve symptoms of seasonal affective disorder (SAD), also known as winter depression or “winter blues.”  Patients with SAD often have normal mental health throughout the year except in one season, most commonly winter, during which they experience symptoms of depression.

Oxytocin: the love bug

Though the hormone oxytocin is most commonly associated with its functions in female reproduction, recent studies have brought to light oxytocin’s role in regulating feelings of love, empathy, and connection to others, giving oxytocin its reputation for being the “love hormone.”  In a landmark article published in Proceedings of the National Academy of Sciences in 1992, oxytocin binding in the brain of a female prairie vole during sexual activity was found to be important for pair bonding in the brain was observed.  Additionally, a 2003 paper published in Nature showed that nasal administration of oxytocin resulted in increased trust among human participants, thus implicating oxytocin in promoting social behaviors and interactions.



what is happiness?

Dr.Sonja Lyubomirsky, PhD

“A combination of frequent positive emotions, plus the sense that your life is good.”

Dr. Martin Seligman, PhD

“The pursuit of engaging and meaningful activities.”

What is happiness NOT?

Dr. Edward Diener, PhD, (aka “Dr. Happiness”):  

"Getting everything right in your life. If you have no goal other than your personal happiness, you’ll never achieve it. If you want to be happy, pursue something else vigorously and happiness will catch up with you.”

But even the experts agree: no one can define happiness for you.  You define it for yourself. 


Spring 2011| Vol. 11| Issue 4

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