Happiness

Abstract

Happiness is a type of emotion: in the research literature it names subjective well-being, the combination of how satisfied people judge their lives to be and how pleasant their everyday feelings are. This article covers how happiness is defined and measured, its heritable set point and the adaptation that returns people toward it, the relation between income and happiness and the dispute over whether it plateaus, the activities and interventions that have been shown to raise it, its correlates in the brain, and its association with health and longevity. The central dispute is whether emotional well-being stops rising with income, a question two laboratories resolved by collaborating on their own conflicting data. Three interactive demos show how set point, circumstances and activity combine, how a life event is adapted to, and how the two measures of happiness track income.

Keywords: happiness, subjective well-being, life satisfaction, positive affect

Happiness entered psychology as a demographic portrait and left as a process. In 1967 a broad review concluded that the happy person is a young, healthy, well-educated, well-paid, extroverted, optimistic, worry-free, religious, married person with high self-esteem, job morale, modest aspirations, of either sex and of a wide range of intelligence; in the three decades since, a number of those conclusions were overturned, youth and modest aspirations are no longer seen as prerequisites, and researchers became less interested in describing the demographic correlates of well-being than in understanding the processes that underlie it (Diener et al., 1999). The same review set out what remained to be done: to examine the causal direction of the correlates, to take person-by-situation interactions into account, to understand the processes underlying adaptation, and to make specific predictions about how input variables differentially influence the components of subjective well-being (Diener et al., 1999). The quarter century of work reviewed below is largely an answer to that agenda.

What Happiness Is

Psychology studies happiness under the name subjective well-being, and the first thing it established is that the construct has parts. Researchers once treated well-being as a monolithic entity, but it is now clear that there are separable components that exhibit unique patterns of relations with different variables: life satisfaction, pleasant affect and unpleasant affect (Diener et al., 1999). A later analysis of more than 450,000 responses to a daily United States survey distinguished emotional well-being, the emotional quality of an individual's everyday experience, the frequency and intensity of experiences of joy, stress, sadness, anger and affection that make life pleasant or unpleasant, from life evaluation, the thoughts people have about their life when they think about it, and found that the two have different correlates (Kahneman & Deaton, 2010). Income and education are more closely related to life evaluation, while health, care giving, loneliness and smoking are relatively stronger predictors of daily emotions (Kahneman & Deaton, 2010).

Figure 1

The Components of Subjective Well-Being and Their Instruments

A third strand asks whether happiness is everything, and explores the meaning of psychological well-being beyond it (Ryff, 1989). A three-way division distinguishes evaluative well-being or life satisfaction, hedonic well-being, the feelings of happiness, sadness, anger, stress and pain, and eudemonic well-being, the sense of purpose and meaning in life (Steptoe et al., 2015). The field that organised this work defines itself by its subject matter. A science of positive subjective experience, positive individual traits and positive institutions promises to improve quality of life and prevent the pathologies that arise when life is barren and meaningless, against a discipline whose exclusive focus on pathology had produced a model of the human being lacking the positive features that make life worth living (Seligman & Csikszentmihalyi, 2000). Happiness, on this account, is one of the things psychology had to learn to count.

Measuring Happiness

Each component has its instrument. The Satisfaction With Life Scale was developed to measure global life satisfaction; among the components of subjective well-being it is narrowly focused and does not tap related constructs such as positive affect or loneliness, shows high internal consistency and high temporal reliability, and correlates moderately to highly with other measures of subjective well-being and predictably with specific personality characteristics (Diener et al., 1985). For affect, positive and negative affect had consistently emerged as two dominant and relatively independent dimensions, and the Positive and Negative Affect Schedule supplied two 10-item mood scales that are highly internally consistent, largely uncorrelated, and stable at appropriate levels over a two-month period (Watson et al., 1988).

Experienced well-being needs a different method, because recall is biased. The Day Reconstruction Method assesses how people spend their time and how they experience the activities and settings of their lives, combining features of time-budget measurement and experience sampling; participants systematically reconstruct the preceding day with procedures designed to reduce recall biases, and its utility was shown by close correspondences between the reports of 909 employed women and established results from experience sampling (Kahneman et al., 2004). Experience sampling itself moved onto the telephone: an iPhone application revealed that wandering thoughts lead to unhappiness (Killingsworth & Gilbert, 2010). A recent review of the field describes the validity of its measures and their potential biases, the scientific methods used, and the national accounts of subjective well-being now being considered and adopted to inform policy at the community and societal levels (Diener et al., 2018).

Set Point, Adaptation and Heritability

Happiness is stable in a way that circumstances are not. In a birth-record-based sample of several thousand middle-aged twins, neither socioeconomic status, educational attainment, family income, marital status nor an indicant of religious commitment could account for more than about 3% of the variance in well-being, whereas from 44% to 52% of the variance was associated with genetic variation; from retests of smaller samples after intervals of four and a half and ten years, the heritability of the stable component of subjective well-being was estimated to approach 80% (Lykken & Tellegen, 1996). Later and larger samples give lower figures: a systematic search identified 30 twin-family studies on well-being or a related measure, with heritability estimates ranging from 0 to 64%, and sample-size-weighted meta-analyses put the heritability of well-being at 36% in 55,974 individuals and that of satisfaction with life at 32% in 47,750 (Bartels, 2015). The stability was read, for a time, as a treadmill. An early test compared 22 major lottery winners with 22 controls and with a group of 29 paralysed accident victims who had been interviewed previously: as adaptation level theory predicted, lottery winners were not happier than controls and took significantly less pleasure from a series of mundane events (Brickman et al., 1978). According to the hedonic treadmill model, good and bad events temporarily affect happiness but people quickly adapt back to hedonic neutrality, which implies that individual and societal efforts to increase happiness are doomed to failure (Diener et al., 2006).

The treadmill needed revising. Recent empirical work indicates five revisions: individuals' set points are not hedonically neutral; people have different set points, partly dependent on their temperaments; a single person may have multiple set points, since pleasant emotions, unpleasant emotions and life satisfaction can move in different directions; well-being set points can change under some conditions; and individuals differ in their adaptation to events, with some changing their set point and others not (Diener et al., 2006). The longitudinal evidence shows the last point directly. In a 15-year study of over 24,000 individuals, people on average reacted to marital transitions and then adapted back toward baseline, but there were substantial individual differences: individuals who initially reacted strongly were still far from baseline years later, many showed trajectories in the opposite direction to that predicted by adaptation theory, and marital transitions can be associated with long-lasting changes in satisfaction that are overlooked when only average trends are examined (Lucas et al., 2003).

What the happiest people look like has also been checked. When 222 undergraduates were screened for high happiness with multiple confirming filters and the upper 10% compared with average and very unhappy people, the very happy were highly social, had stronger romantic and other social relationships, were more extroverted, more agreeable and less neurotic, and scored lower on several psychopathology scales; they did not exercise significantly more, participate in religious activities more, or experience more objectively defined good events (Diener & Seligman, 2002). No variable was sufficient for happiness, but good social relations were necessary, and the happiest group experienced positive but not ecstatic feelings most of the time with occasional negative moods, which suggests that very happy people have a functioning emotion system that can react appropriately to life events (Diener & Seligman, 2002).

Money and Happiness

The relation between income and happiness depends on the time scale, the level of analysis and the measure. Across countries, the striking thing about the happiness-income paradox is that over the long term, usually a period of ten years or more, happiness does not increase as a country's income rises; the long-term nil relationship holds for developing countries, for eastern European countries transitioning from socialism and for a wide sample of developed countries, while in the short term happiness and income go together, falling in contractions and rising in expansions (Easterlin et al., 2010). A reassessment of the paradox that analysed multiple rich datasets spanning many decades reached the opposite reading: a clear positive link between average levels of subjective well-being and GDP per capita across countries, no evidence of a satiation point beyond which wealthier countries have no further increases in subjective well-being, and, within countries over time, economic growth associated with rising happiness, which the authors took to indicate a clear role for absolute income and a more limited role for relative income comparisons (Stevenson & Wolfers, 2008). Within a country the picture differs by measure. When plotted against log income, life evaluation rises steadily; emotional well-being also rises with log income, but in the daily survey of United States residents there was no further progress beyond an annual income of about 75,000 dollars, so that high income buys life satisfaction but not happiness, while low income is associated both with low life evaluation and low emotional well-being and exacerbates the emotional pain of misfortunes such as divorce, ill health and being alone (Kahneman & Deaton, 2010).

The plateau became the focus of substantial attention from researchers and the general public (Killingsworth, 2021). Using the Gallup World Poll, a representative sample of over 1.7 million individuals worldwide, spline regression models identified points of income satiation globally at 95,000 dollars for life evaluation and 60,000 to 75,000 dollars for emotional well-being, with substantial variation across world regions, satiation occurring later in wealthier regions, and incomes beyond satiation associated in some parts of the world with lower life evaluations (Jebb et al., 2018). Then over one million real-time reports of experienced well-being from a large United States sample showed experienced well-being rising linearly with log income, with an equally steep slope above 80,000 dollars as below it, suggesting that higher incomes may still improve day-to-day well-being rather than having reached a plateau (Killingsworth, 2021).

Table 1. Income and happiness in the cited studies, as reported in their abstracts.

Note. Each row lists only what the cited abstracts report (Easterlin et al., 2010; Kahneman & Deaton, 2010; Jebb et al., 2018; Killingsworth, 2021; Killingsworth et al., 2023). Data, measures and currencies of reference differ, so the rows are not directly comparable.

The two laboratories then collaborated on their own disagreement. A reanalysis of the experience-sampling data confirmed the flattening pattern only for the least happy people: happiness increases steadily with log income among happier people and even accelerates in the happiest group, and complementary nonlinearities contribute to the overall linear-log relationship (Killingsworth et al., 2023). The earlier study had overstated the flattening because its dichotomous measures could not discriminate among degrees of happiness owing to a ceiling effect and might have reached the correct conclusion had it described its results in terms of unhappiness rather than happiness, while the later study had failed to find the flattening; both had failed to anticipate that increased income is associated with systematic changes in the shape of the happiness distribution (Killingsworth et al., 2023). The collaboration also noted that the relationship is weak even if statistically robust: the correlation between average happiness and log income was 0.09 in the experience-sampling data, the difference between the medians of happiness at household incomes of 15,000 and 250,000 dollars was about five points on a 100-point scale, and the flattening and accelerating patterns are even smaller modulations of a small effect (Killingsworth et al., 2023). How money is spent matters too: spending more of one's income on others predicted greater happiness both cross-sectionally in a nationally representative survey and longitudinally in a field study of windfall spending, and participants randomly assigned to spend money on others experienced greater happiness than those assigned to spend it on themselves (Dunn et al., 2008). Because most studies on prosocial spending had used small samples, the central paradigms were later put to high-powered registered replications: 712 students randomly assigned to make a purchase for themselves or a stranger in need reported greater momentary happiness after prosocial spending, as predicted; 1,950 adults who recalled a time they spent money on themselves or someone else did not, contrary to predictions, report greater happiness in the prosocial condition; and in a third experiment of 5,199 participants with changes designed to increase engagement, those who recalled a prosocial spending memory reported greater happiness but the differences were small, so that the studies support the hypothesis that spending money on others does promote happiness while showing that the magnitude of the effect depends on several methodological features (Aknin et al., 2020).

What Raises Happiness

If set points can move, the question is what moves them. The sustainable happiness model proposes that a person's chronic happiness level is governed by three major factors, a genetically determined set point, happiness-relevant circumstantial factors, and happiness-relevant activities and practices, and argues from adaptation and dynamic processes that the activity category offers the best opportunities for sustainably increasing happiness (Lyubomirsky et al., 2005). A controlled test followed. In a six-group, random-assignment, placebo-controlled Internet study of five purported happiness interventions and one plausible control exercise, three of the interventions lastingly increased happiness and decreased depressive symptoms (Seligman et al., 2005).

The mechanism has since been modelled. According to the positive-activity model, features of positive activities such as their dosage and variety, features of persons such as their motivation and effort, and person-activity fit moderate the effect of positive activities on well-being, through four mediating variables: positive emotions, positive thoughts, positive behaviours and need satisfaction (Lyubomirsky & Layous, 2013). The theory behind the first of those mediators holds that experiences of positive emotions broaden people's momentary thought-action repertoires, which in turn serves to build their enduring personal resources, ranging from physical and intellectual to social and psychological, so that the capacity to experience positive emotions may be a fundamental human strength (Fredrickson, 2001). The popular version of this literature has outrun its evidence, however. By coding media articles on happiness, a systematic review identified the five most commonly recommended strategies, expressing gratitude, enhancing sociability, exercising, practising mindfulness or meditation and increasing nature exposure, then searched for well-powered, pre-registered experiments testing them in non-clinical samples; 57 studies were included, and the review concluded that a strong scientific foundation is lacking for some of the most commonly recommended happiness strategies, whose effectiveness remains an open question (Folk & Dunn, 2023).

The Brain and the Body

Well-being has a resting signature in the prefrontal cortex. Despite a vast literature implicating asymmetric prefrontal activation in approach-withdrawal motivation and emotion, no published report had directly explored the neural correlates of well-being until 84 right-handed adults aged 57 to 60 completed self-report measures of eudaimonic well-being, hedonic well-being and positive affect before resting electroencephalography; as hypothesised, greater left than right superior frontal activation was associated with higher levels of both forms of well-being, and hemisphere-specific analyses documented the importance of goal-directed approach tendencies beyond approach-related positive affect for eudaimonic but not hedonic well-being (Urry et al., 2004). The authors suggest that appropriately engaging sources of appetitive motivation, characteristic of higher left than right baseline prefrontal activation, may encourage the experience of well-being (Urry et al., 2004).

Below the brain, the mechanisms that could link happiness with health include lifestyle factors such as physical activity and dietary choice, and biological processes involving neuroendocrine, inflammatory and metabolic pathways (Steptoe, 2019). Happiness in this literature encompasses several constructs, affective well-being, eudaimonic well-being and evaluative well-being, and interventions have yet to demonstrate substantial, sustained improvements in subjective well-being or a direct impact on physical health outcomes (Steptoe, 2019). The body is where the claim that happiness is good for a person has to be cashed, and the cashing is incomplete.

Happiness and Health

Happiness predicts outcomes as well as following from them. Numerous studies show that happy individuals are successful across multiple life domains, including marriage, friendship, income, work performance and health; a conceptual model holds that the happiness-success link exists not only because success makes people happy but because positive affect engenders success, and cross-sectional, longitudinal and experimental evidence combined meta-analytically reveals that happiness is associated with and precedes numerous successful outcomes, so that positive affect may be the cause of many of the desirable characteristics, resources and successes correlated with happiness (Lyubomirsky et al., 2005). Higher subjective well-being has likewise been associated with good health and longevity, better social relationships, work performance and creativity (Diener et al., 2018).

In an analysis of the English Longitudinal Study of Ageing, eudemonic well-being was associated with increased survival: 29.3% of people in the lowest well-being quartile died during an average follow-up of 8.5 years compared with 9.3% of those in the highest quartile, with associations independent of age, sex, demographic factors and baseline mental and physical health; the same review found a U-shaped relation between evaluative well-being and age in high-income English-speaking countries, lowest at ages 45 to 54, but not universally, and concluded that the association between well-being and survival is consistent with a protective role of high well-being although alternative explanations cannot be ruled out (Steptoe et al., 2015). Across prospective observational studies happiness is generally associated with reduced mortality, albeit with several discrepant results, and confounding and reverse causation are major concerns, since impaired happiness may be not only a consequence of ill health but a contributor to disease risk (Steptoe, 2019). The relation between physical health and subjective well-being is bidirectional: older people with illnesses such as coronary heart disease, arthritis and chronic lung disease show both increased depressed mood and impaired hedonic and eudemonic well-being (Steptoe et al., 2015).

Worked Example

The numbers in this literature divide into three kinds, and each repays a check. The twin study attributes 44% to 52% of the variance in well-being to genetic variation and no more than about 3% to any of socioeconomic status, education, income, marital status or religious commitment (Lykken & Tellegen, 1996); at the midpoint, 48%, genes account for at least about sixteen times as much variance as any one of those demographic factors, and the estimated 80% heritability of the stable component means that of the part of well-being that does not fluctuate, four fifths tracks genetic variation. The survival analysis reports 29.3% mortality in the lowest well-being quartile against 9.3% in the highest over an average of 8.5 years (Steptoe et al., 2015): the ratio 29.3 / 9.3 is 3.2, so people in the lowest quartile were about three times as likely to die, and the absolute difference is 20 percentage points.

The income numbers show how a measure shapes a conclusion. The daily survey analysis rests on more than 450,000 responses at 1,000 residents a day (Kahneman & Deaton, 2010), which is at least 450 days of surveying, about fifteen months. It placed the emotional-well-being plateau at about 75,000 dollars; the global study put satiation at 95,000 dollars for life evaluation and 60,000 to 75,000 dollars for emotional well-being across 1.7 million respondents (Jebb et al., 2018), so the two emotional estimates overlap at their upper bound; and the experience-sampling study, with over one million reports, found an equally steep slope above 80,000 dollars as below (Killingsworth, 2021). The intervention trial tested five interventions and found three lasting (Seligman et al., 2005), a 60% success rate in a single study, while the systematic review found 57 well-powered pre-registered studies across five recommended strategies (Folk & Dunn, 2023), an average of about eleven per strategy for the five most recommended practices in the popular literature.

Discussion

Three lessons follow for cognitive psychology. First, the components of happiness are not interchangeable. Life satisfaction and emotional well-being have different correlates (Kahneman & Deaton, 2010), the components can move in different directions within one person (Diener et al., 2006), and goal-directed approach tendencies mattered beyond approach-related positive affect for eudaimonic but not hedonic well-being, although greater left than right frontal activation accompanied both (Urry et al., 2004). The 1999 review asked for theories that explain why variables differentially influence the components (Diener et al., 1999), and the income debate shows why: a plateau in a given component is not a plateau in another.

Second, measurement decides results. The adversarial collaboration found that a dichotomous daily measure could not discriminate among degrees of happiness because of a ceiling effect, and that both groups had failed to anticipate that income changes the shape of the happiness distribution (Killingsworth et al., 2023); the day reconstruction method exists because recall is biased (Kahneman et al., 2004); and the long-term nil relation between national income and happiness was defended against critiques said to rest on a statistical artefact or a confusion of short-term with long-term relations (Easterlin et al., 2010). The authors of the collaboration flag that the mislabelling of a dependent variable and the assumption of homogeneity were consequences of practices standard in social science that should be questioned more often (Killingsworth et al., 2023).

Third, the case that happiness can be raised is real but narrower than its popular form. The sustainable happiness model argues that activity, not circumstance, is where durable gains lie (Lyubomirsky et al., 2005), and three of five interventions lastingly increased happiness in a placebo-controlled trial (Seligman et al., 2005); but set points can change only under some conditions (Diener et al., 2006), interventions have yet to show substantial sustained improvements with direct impact on physical health (Steptoe, 2019), and some of the strategies most recommended in the media lack a strong scientific foundation (Folk & Dunn, 2023). What the evidence supports is that happiness is partly a disposition and partly a response to circumstance that fades (Lyubomirsky et al., 2005), and partly a practice whose effects depend on the person, the activity and their fit (Lyubomirsky & Layous, 2013).

Current Directions

The research front is methodological, economic and medical. In measurement, the recent review of subjective well-being describes the validity of its measures and their potential biases and notes that national accounts of subjective well-being are now being considered and adopted to inform policy (Diener et al., 2018), while the adversarial collaboration on income presses the field to question the labelling of dependent variables and the assumption of homogeneity (Killingsworth et al., 2023). In economics, the finding that incomes beyond satiation are associated in some regions with lower life evaluations (Jebb et al., 2018) and the finding that spending on others raises happiness (Dunn et al., 2008), an effect whose magnitude a registered replication found to depend on several methodological features (Aknin et al., 2020), have moved attention from how much money people have to how it is used. In health, the possibility that impaired happiness contributes to disease risk through neuroendocrine, inflammatory and metabolic pathways is described as a field of great potential with the promise of a favourable effect on population health (Steptoe, 2019), and the well-being of elderly people is proposed as an objective for both economic and health policy (Steptoe et al., 2015). In intervention science, the systematic review of recommended strategies calls for well-powered, pre-registered studies of strategies for promoting happiness (Folk & Dunn, 2023), and the positive-activity model supplies the moderators and mediators such studies would test (Lyubomirsky & Layous, 2013).

Common Misconceptions

“Happiness is one thing.”

Subjective well-being has separable components, life satisfaction, pleasant affect and unpleasant affect, with unique patterns of relations to different variables (Diener et al., 1999), and emotional well-being and life evaluation have different correlates, income tracking the second more than the first (Kahneman & Deaton, 2010).

“Money cannot buy happiness.”

Life evaluation rises steadily with log income and low income exacerbates the emotional pain of misfortune (Kahneman & Deaton, 2010); in over one million real-time reports, experienced well-being rose linearly with log income with an equally steep slope above 80,000 dollars as below (Killingsworth, 2021). The disagreement between those two studies concerned the plateau, not the slope (Killingsworth et al., 2023); the collaboration also noted that the relationship is weak even if statistically robust, with a correlation of 0.09 between average happiness and log income (Killingsworth et al., 2023).

“Happiness is fixed by genes, so nothing can change it.”

In a 1996 twin study, 44% to 52% of the variance in well-being was associated with genetic variation, not all of it (Lykken & Tellegen, 1996); well-being set points can change under some conditions (Diener et al., 2006), and three of five interventions lastingly increased happiness in a placebo-controlled trial (Seligman et al., 2005).

“Gratitude journals, exercise and meditation are proven to make people happier.”

A systematic review of well-powered, pre-registered experiments on the five most commonly recommended strategies found 57 studies and concluded that a strong scientific foundation is lacking for some of them, their effectiveness remaining an open question (Folk & Dunn, 2023).

Glossary

Adversarial collaboration.

A joint analysis by researchers who have published contradictory results, used to resolve whether emotional well-being plateaus with income.

Broaden-and-build theory.

The proposal that positive emotions broaden momentary thought-action repertoires and thereby build enduring physical, intellectual, social and psychological resources.

Day Reconstruction Method.

A survey method in which participants reconstruct the previous day's activities and experiences with procedures designed to reduce recall bias, combining time-budget measurement and experience sampling.

Emotional well-being.

The emotional quality of everyday experience, the frequency and intensity of joy, stress, sadness, anger and affection; also called hedonic or experienced well-being.

Eudaimonic well-being.

The sense of purpose and meaning in life; associated with increased survival in older adults and with approach-related prefrontal asymmetry.

Experience sampling.

Repeated real-time reports of feelings and activities during daily life, now collected by telephone application.

Happiness-income paradox.

The disputed finding that over the long term national happiness does not increase as a country's income rises, although the two move together in the short term; a reassessment of broader data reported a positive link instead.

Hedonic treadmill.

The model on which good and bad events affect happiness only temporarily before people adapt back to neutrality; its early evidence was the 1978 comparison of lottery winners, controls and accident victims, and it was revised in five respects by later evidence.

Income satiation.

The income beyond which higher income is no longer associated with greater well-being; estimated globally at 95,000 dollars for life evaluation and 60,000 to 75,000 dollars for emotional well-being.

Life evaluation.

The thoughts people have about their life when they think about it; the component of well-being most closely related to income and education.

Positive activity model.

The model on which features of activities, features of persons and person-activity fit moderate the effect of positive activities on well-being, through positive emotions, thoughts, behaviours and need satisfaction.

Positive and Negative Affect Schedule.

Two 10-item mood scales measuring the two dominant and relatively independent dimensions of affect.

Positive psychology.

The science of positive subjective experience, positive individual traits and positive institutions, proposed as a corrective to a discipline focused on pathology.

Satisfaction With Life Scale.

A brief, narrowly focused measure of global life satisfaction with high internal consistency and temporal reliability.

Set point.

A person's characteristic level of well-being toward which they tend to return after events; partly genetic, not neutral, different between people and capable of change under some conditions.

Subjective well-being.

The scientific term for happiness: a person's own evaluation of their life, comprising life satisfaction, pleasant affect and unpleasant affect.

Sustainable happiness model.

The proposal that chronic happiness is governed by a genetic set point, circumstances and intentional activities, with activity the best route to durable change.

Key Researchers

Ed Diener

(1946-2021). Joseph R. Smiley Distinguished Professor of Psychology Emeritus at the University of Illinois at Urbana-Champaign, later at the Universities of Utah and Virginia; defined subjective well-being as the scientific construct behind happiness, authored the Satisfaction With Life Scale, and reviewed three decades of its research. ORCID - Wikipedia - Google Scholar

Elizabeth W. Dunn

. Professor of Psychology at the University of British Columbia; found that spending money on others promotes happiness, co-authored its registered replication, and systematically reviewed the strength of evidence behind the happiness strategies most recommended in the media. Faculty Page - Wikipedia - Google Scholar

Barbara L. Fredrickson

. Kenan Distinguished Professor of Psychology and Neuroscience at the University of North Carolina at Chapel Hill; proposed the broaden-and-build theory, on which positive emotions widen momentary thought-action repertoires and build enduring personal resources. ORCID - Wikipedia

Daniel Kahneman

(1934-2024). Eugene Higgins Professor of Psychology Emeritus at Princeton University; developed the day reconstruction method for measuring experienced well-being and, with Deaton, separated emotional well-being from life evaluation in their relation to income. Wikipedia - Google Scholar

Matthew A. Killingsworth

. Senior Fellow at the Wharton School, University of Pennsylvania; built a large telephone-based experience-sampling project, showed that a wandering mind is an unhappy one, and found that experienced well-being rises with income without a plateau. Faculty Page

Sonja Lyubomirsky

. Distinguished Professor of Psychology at the University of California, Riverside; proposed the sustainable happiness model partitioning well-being into set point, circumstances and intentional activity, and tested the positive activities that raise it. ORCID - Wikipedia - Google Scholar

Carol D. Ryff

. Hilldale Professor of Psychology at the University of Wisconsin-Madison and director of its Institute on Aging; proposed the six-dimension model of psychological well-being that set eudaimonic well-being beside hedonic happiness. Wikipedia - Google Scholar

Martin E. P. Seligman

. Zellerbach Family Professor of Psychology and director of the Positive Psychology Center at the University of Pennsylvania; launched positive psychology as a field and ran a six-group, randomised, placebo-controlled test of positive interventions on happiness. Faculty Page - Wikipedia

Frequently Asked Questions

What is happiness in psychology?

Psychology studies happiness as subjective well-being, which has separable components: life satisfaction, pleasant affect and unpleasant affect (Diener et al., 1999); a common three-way division distinguishes evaluative, hedonic and eudemonic well-being (Steptoe et al., 2015).

How is happiness measured?

Life satisfaction with the Satisfaction With Life Scale (Diener et al., 1985), affect with the Positive and Negative Affect Schedule (Watson et al., 1988), and experienced well-being with the Day Reconstruction Method (Kahneman et al., 2004) or real-time experience sampling by telephone (Killingsworth & Gilbert, 2010).

Is happiness genetic?

Partly. In a twin sample, 44% to 52% of the variance in well-being was associated with genetic variation and the heritability of its stable component was estimated to approach 80%, while demographic factors each accounted for no more than about 3% (Lykken & Tellegen, 1996); a later meta-analysis of 55,974 individuals put the weighted average heritability of well-being at 36% (Bartels, 2015).

Do people adapt to everything?

On average people react to events and adapt back toward baseline, but individuals who reacted strongly to marital transitions were still far from baseline years later and many moved in the opposite direction (Lucas et al., 2003); set points are not neutral, differ between people, and can change (Diener et al., 2006).

Does money make people happier?

Life evaluation rises steadily with log income (Kahneman & Deaton, 2010); whether emotional well-being plateaus is contested, with a plateau near 75,000 dollars in one survey (Kahneman & Deaton, 2010), satiation at 60,000 to 75,000 dollars globally (Jebb et al., 2018), and no plateau in experience-sampling data (Killingsworth, 2021); a joint reanalysis found flattening only among the least happy people (Killingsworth et al., 2023).

Can people make themselves happier?

The sustainable happiness model holds that intentional activities offer the best opportunity (Lyubomirsky et al., 2005), three of five interventions lastingly increased happiness in a placebo-controlled trial (Seligman et al., 2005), and spending on others raised happiness in a randomised assignment (Dunn et al., 2008), an effect that a registered replication supported while finding its magnitude dependent on several methodological features (Aknin et al., 2020); some of the most commonly recommended strategies, however, lack a strong scientific foundation (Folk & Dunn, 2023).

What happens in the brain of a happy person?

In 84 older adults, greater left than right superior frontal activation at rest was associated with higher eudaimonic and hedonic well-being, with goal-directed approach tendencies mattering for eudaimonic well-being in particular (Urry et al., 2004).

Does happiness affect health?

Eudemonic well-being was associated with increased survival in the English Longitudinal Study of Ageing, with 29.3% of the lowest quartile dying over 8.5 years against 9.3% of the highest (Steptoe et al., 2015); happiness is generally associated with reduced mortality in prospective studies, though confounding and reverse causation are major concerns (Steptoe, 2019).

References