This blog reports new ideas and work on mind, brain, behavior, psychology, and politics - as well as random curious stuff. (Try the Dynamic Views at top of right column.)
Blanceflower and Oswald have done a fascinating study (PDF here) showing that across cultures, from Azerbaijan to Zimbabwe, we are happiest towards the beginning and end of our lives, leaving us most miserable in middle years between 40 and 50. For both men and women in the UK, the probability of depression peaked at around the age of 44. In the US, men were most likely to be unhappiest at 50, while for women the age was 40. The cause of the apparent U-shaped curve is not known. Quoting Oswald (the graphic is from his website):
...one possibility is that individuals learn to adapt to their strengths and weaknesses, and in mid-life quell their infeasible aspirations. Another possibility is that cheerful people live systematically longer...A third possibility is that older people might compare their lives with their peers'. Seeing their friends die could mean people value their remaining years more highly...It looks from the data like something happens deep inside humans. For the average person in the modern world, the dip in mental health and happiness comes on slowly, not suddenly in a single year...Only in their 50s do most people emerge from the low period. But encouragingly, by the time you are 70, if you are still physically fit then on average you are as happy and mentally healthy as a 20-year-old. Perhaps realising that such feelings are completely normal in mid-life might even help individuals survive this phase better.
This little bit of work notes the neural basis of some of our 'refined aesthetic preferences'...what your brain might be doing when you feel that something that costs more is better (even when you are unknowingly comparing identical items). Here is the abstract from Plassmann et al.:
Despite the importance and pervasiveness of marketing, almost nothing is known about the neural mechanisms through which it affects decisions made by individuals. We propose that marketing actions, such as changes in the price of a product, can affect neural representations of experienced pleasantness. We tested this hypothesis by scanning human subjects using functional MRI while they tasted wines that, contrary to reality, they believed to be different and sold at different prices. Our results show that increasing the price of a wine increases subjective reports of flavor pleasantness as well as blood-oxygen-level-dependent activity in medial orbitofrontal cortex, an area that is widely thought to encode for experienced pleasantness during experiential tasks. The paper provides evidence for the ability of marketing actions to modulate neural correlates of experienced pleasantness and for the mechanisms through which the effect operates.
Figure: Neural correlates of liking ratings. (A) Activity in the mOFC and the midbrain correlated with the reported pleasantness of the six liquids at degustationtime. (B) Correlationof pleasantness ratings and BOLD responses
This short piece by Marina Krakovsky from the NY Times:
People often display a remarkable ability to adapt to adversity, bouncing back to their usual levels of happiness despite extreme hardships. But people don’t always rebound, and scientists have long wondered what factors might account for the difference. In a talk at Harvard in September, a team of researchers suggested that one obstacle to emotional recovery, oddly enough, is hope — the belief that your current hardship is temporary.
From the beginning, the investigators suspected that hope might sometimes be counterproductive: prisoners with life sentences but with the possibility of parole adapt less well to prison life, for example, than prisoners with life sentences without the possibility of parole. But the researchers sought another empirical test. Their choice: Colostomy patients. The research team, led by Peter Ubel, a physician at the University of Michigan, tracked people who had portions of their colons removed or bypassed, such that the patients couldn’t defecate normally. The condition is extremely unpleasant and leads many people to say they’d rather be dead, Ubel reports. But a colostomy isn’t always permanent. Some patients are likely to heal and have their bowels reconnected. Whether your colostomy is permanent depends on your condition, but were it up to the patient to choose, “almost anybody would choose temporary over permanent,” Ubel says.
So it’s surprising that the permanent-colostomy patients ended up happier six months after the operation than the temporary group, whose members were still holding out hope. Patients with a temporary colostomy experienced a significant drop in life satisfaction versus patients in the permanent group.
It might seem strange that patients who are better off objectively were less satisfied with their lives, yet the finding makes sense: “If your condition is temporary,” Ubel explains, “you’re thinking, I can’t wait until I get rid of this.” Ubel says thoughts like these keep you from moving on with your life and focusing on the many good things that remain.
Sharot et al. examine the tendency of most of us to imagine more optimistic outcomes than can be justified by sober appraisal. A moderate amount of optimistic illusion has been related to mental and physical health, and the general idea is that it is adaptive and useful because it motivates us towards future goals. Their abstract, and a figure showing the relevant brain regions:
Humans expect positive events in the future even when there is no evidence to support such expectations. For example, people expect to live longer and be healthier than average, they underestimate their likelihood of getting a divorce, and overestimate their prospects for success on the job market. We examined how the brain generates this pervasive optimism bias. Here we report that this tendency was related specifically to enhanced activation in the amygdala and in the rostral anterior cingulate cortex when imagining positive future events relative to negative ones, suggesting a key role for areas involved in monitoring emotional salience in mediating the optimism bias. These are the same regions that show irregularities in depression, which has been related to pessimism. Across individuals, activity in the rostral anterior cingulate cortex was correlated with trait optimism. The current study highlights how the brain may generate the tendency to engage in the projection of positive future events, suggesting that the effective integration and regulation of emotional and autobiographical information supports the projection of positive future events in healthy individuals, and is related to optimism.
The authors collected functional magnetic resonance imaging (fMRI) data while participants thought of autobiographical events related to a description of a life episode (for example, 'winning an award' or 'the end of a romantic relationship'). The word 'past' or 'future' indicated if they should think of an event that occurred in the past or one that might occur in the future. Trials were classified into positive, negative and neutral according to participants' ratings. They found that future positive events were rated as more positive than past positive events, and were imagined to be closer in temporal proximity then future negative events and all past events. (Click on image to enlarge it)
PLoS Biology has ventured beyond its usual fare to publish several articles focusing on poverty, human development, and the environment. This article is from Eric Brunner. He points out several studies that demonstrate a direct psychosocial pathway to disease. It's precis: "Intriguing parallels between civil servant and nonhuman primate hierarchies suggest that highly stratified societies foster health inequalities. Determining how social differences translate into chronic disease remains a challenge, but neuroendocrine pathways appear to play a role."
Gilbert and Wilson offer a concise review of our unique human ability to simulate the future, covering brain regions involved and stereotyped errors that occur (PDF here). (I did a series of posts in June, 2006 abstracting Gilberts book "Stumbling on Happiness." You can use the blog search box to find them by entering the word "stumbling.") Here are some clips:
Prefeelings will be reliable predictors of subsequent hedonicexperiences when two conditions are met. As the figure shows, whenwe are in the present (T1) attempting to predict our hedonicreaction to an event in the future (H2), our present hedonicexperience (H1) is influenced by our simulation of the futureevent (e1) as well as by contextual factors (1), such as theevents that are occurring in the present, the thoughts we arehaving in the present, our present bodily states, and so on.We feel better when we imagine going to the theater than tothe dentist, but we feel better imagining either event on asunny day than on a rainy day, or when we are well rather thanill. Similarly, our future hedonic experience (H2) will be influencedboth by our perception of the event (e2) and by contextual factors(2). Because our hedonic experiences are influenced both byour mental representation of the event and by contextual factors,our present hedonic experience will be a reliable predictorof our future hedonic experience if and only if (i) our simulationof the event at T1 exerts the same influence on our hedonicexperience at T1 as our perception of the event at T2 exertson our hedonic experience at T2, and (ii) contextual factorsat T1 exert the same influence on our hedonic experience atT1 as contextual factors at T2 exert on our hedonic experienceat T2. In other words, H1 = H2 if and only if e1 = e2 and 1= 2. Errors in prospection arise from the fact that people usetheir prefeelings to make hedonic predictions even when oneor both of these conditions is not met. These errors are offour kinds.
Simulations are unrepresentative. We naturally imagine our next dental appointment by remembering our last one.... research suggests that people often use unrepresentative memories as a basis for simulation. For example, when people who have missed trains in the past are asked to imagine missing a train in the future, they tend to remember their worst train-missing experience rather than their typical train-missing experience.
Simulations are essentialized. When we imagine "going to the theater next week," we don't imagine every detail of the event, but rather, we imagine the essential features that define it. We imagine seeing a stage filled with actors but we do not imagine parking the car, checking our coat, or finding our seat. The problem with omitting inessential features from simulations is that such features can profoundly influence our subsequent hedonic experience... Because simulations omit inessential features, people tend to predict that good events will be better and bad events will be worse than they actually turn out to be. The young couple who simulate the joys of parenthood but fail to simulate the drudgery of diapers are unlikely to have the hedonic experience they imagined.
Simulations are abbreviated. If we imagined each and every moment of the events we were simulating, our simulations would take as long as the events themselves. Simulations are naturally abbreviated and represent just a few, select moments of a future event. The moments they select tend to be the early ones. When people imagine what their lives would be like if they won the lottery or became paraplegic, they are more likely to imagine the first day than the two-hundred-and-ninety-seventh. The problem with imagining only the early moments of an event is that hedonic reactions to events typically dissipate over time, which means that mental simulations tend to the moments that evoke the most intense pleasure or pain.
Simulations are decontextualized. Research shows that people often do not consider the potentially significant differences between contextual factors at T1 and T2 when using their present hedonic state to predict their future hedonic state. For example, hungry people mistakenly expect to like eating spaghetti for breakfast the next day, and sated people mistakenly expect to dislike eating it for dinner the next day. People who have just exercised mistakenly expect to enjoy drinking water the next day more than do people who are about to exercise (53). In both cases, people do not seem to realize that their present hunger and thirst are influencing their hedonic reactions to simulated future consumption. They ignore the fact that the contextual factors that are presently exerting an influence at T1 (i.e., hunger and thirst) will not exert the same influence at T2.
Their conclusion makes a nice summary of how modern and ancient brain systems interact in imagining possible future feelings:
Mental simulation is the means by which the brain discovers what it already knows. When faced with decisions about future events, the cortex generates simulations, briefly tricking subcortical systems into believing that those events are unfolding in the present and then taking note of the feelings these systems produce. The cortex is interested in feelings because they encode the wisdom that our species has acquired over millennia about the adaptive significance of the events we are perceiving. Alas, actually perceiving a bear is a potentially expensive way to learn about its adaptive significance, and thus evolution has provided us with a method for getting this information in advance of the encounter. When we preview the future and prefeel its consequences, we are soliciting advice from our ancestors.
This method is ingenious but imperfect. The cortex attempts to trick the rest of the brain by impersonating a sensory system. It simulates future events to find out what subcortical structures know, but try as it might, the cortex cannot generate simulations that have all the richness and reality of genuine perceptions. Its simulations are deficient because they are based on a small number of memories, they omit large numbers of features, they do not sustain themselves over time, and they lack context. Compared to sensory perceptions, mental simulations are mere cardboard cut-outs of reality. They are convincing enough to elicit brief hedonic reactions from subcortical systems, but because they differ from perceptions in such fundamental ways, the reactions they elicit may differ as well. Although prospection allows us to navigate time in a way that no other animal can, we still see more than we foresaw.
I enjoyed watching an interview of Tal Ben-Shahar on the John Stewart Daily News shows several days ago, discussing his new book "Happier." He has integrated threads of the positive psychology movement initiated largely by Martin Seligman (see my post on Seligman) to offer the most popular undergraduate course at Harvard. Although I usually have a gag reaction at most of the self-help stuff I see, I thought I would pass on some of the sane happiness tips from his website. And, a quick search at YouTube gets you his promotional video, also shown below.
* 1. Give yourself permission to be human. When we accept emotions — such as fear, sadness, or anxiety — as natural, we are more likely to overcome them. Rejecting our emotions, positive or negative, leads to frustration and unhappiness.
* 2. Happiness lies at the intersection between pleasure and meaning. Whether at work or at home, the goal is to engage in activities that are both personally significant and enjoyable. When this is not feasible, make sure you have happiness boosters, moments throughout the week that provide you with both pleasure and meaning.
* 3. Keep in mind that happiness is mostly dependent on our state of mind, not on our status or the state of our bank account. Barring extreme circumstances, our level of well being is determined by what we choose to focus on (the full or the empty part of the glass) and by our interpretation of external events. For example, do we view failure as catastrophic, or do we see it as a learning opportunity?
* 4. Simplify! We are, generally, too busy, trying to squeeze in more and more activities into less and less time. Quantity influences quality, and we compromise on our happiness by trying to do too much.
* 5. Remember the mind-body connection. What we do — or don't do — with our bodies influences our mind. Regular exercise, adequate sleep, and healthy eating habits lead to both physical and mental health.
* 6. Express gratitude, whenever possible. We too often take our lives for granted. Learn to appreciate and savor the wonderful things in life, from people to food, from nature to a smile.
A recent study by Harbaught et al. finds that three very different things—monetary payoffs to oneself, observing a charity get money, and a warm-glow effect related to free choice—all activate similar neural substrates. Here is their abstract, PDF of article is here.
Civil societies function because people pay taxes and make charitable contributions to provide public goods. One possible motive for charitable contributions, called "pure altruism," is satisfied by increases in the public good no matter the source or intent. Another possible motive, "warm glow," is only fulfilled by an individual's own voluntary donations. Consistent with pure altruism, we find that even mandatory, tax-like transfers to a charity elicit neural activity in areas linked to reward processing. Moreover, neural responses to the charity's financial gains predict voluntary giving. However, consistent with warm glow, neural activity further increases when people make transfers voluntarily. Both pure altruism and warm-glow motives appear to determine the hedonic consequences of financial transfers to the public good.
Figure: Neural response in the ventral striatum to mandatory payoffs for the subject (yellow), the charity (blue), and both (green). (To test for the pure altruism and warm-glow motives, they used functional magnetic resonance imaging while subjects played a dictator game. Subjects received $100 and then made decisions about whether or not to give money to a local food bank. They also observed mandatory, tax-like transfers of their money to the food bank.)
They suggest that: ...This result supports arguments for a common "neural currency" of reward and shows that this model can be applied not just to choice over money, risk, and private consumption goods, but also to more abstract policy choices involving taxation and charitable giving. Our results are also important for understanding why people give money to charitable organizations. First, these transfers are associated with neural activation similar to that which comes from receiving money for oneself. The fact that mandatory transfers to a charity elicit activity in reward-related areas suggests that even mandatory taxation can produce satisfaction for taxpayers. A better understanding of the conditions under which taxation elicits "neural rewards" could prove useful for evaluating the desirability of different tax policies.
An essay by Michael Schermer in the March 2007 issue of the Scientific American (PDF here), briefly notes several recent books on happiness research and emphasizes the point that assumptions about what constitutes happiness vary over time. Take sex:
"A century ago, an average man who had not had sex in three years might have felt proud of his health and forbearance, and a woman might have praised herself for the health and happiness benefits of ten years of abstinence."
Here is a posting and an audio clip on the topic of happiness that you might find interesting. It includes material from Daniel Gilbert at Harvard, whose book "Stumbling Towards Happiness" I abstracted in earlier blog postings. There is a bit of rap music at the start of the audio, before the spoken text begins.
I've always thought of Lotto games as regressive taxation, and have been totally unable to understand why people would play them instead of socking the money away in a savings account. Benedict Carey has written a nice piece in the March 11 New York Times showing how I have completely missed the point.
...lottery tickets are not an investment but a disposable consumer purchase, which changes the equation radically. Like a throwaway lifestyle magazine, lottery tickets engage transforming fantasies: a wine cellar, a pool, a vision of tropical blues and white sand. The difference is that the ticket can deliver.
And as long as the fantasy is possible, even a negligible probability of winning becomes paradoxically reinforcing...One is willing to pay hard cash that it be so real, so objective, that it is actually calculable — by someone, even if not oneself.
Because it is pure luck, the lottery is easy to grasp and allows for plenty of perfectly loopy — and very enjoyable — number superstitions. Your birthday digits never won you a dime? Try your marriage date; your favorite psalm verse; the day your bullying father-in-law died.... psychologists have found that ticket holders are very reluctant to trade their tickets for others, precisely because they have an illusion of control from having picked magical numbers.
This sense of power infuses the waiting period with purpose. And the hope of a huge payoff, however remote, is itself a source of pleasure. In brain-imaging studies of drug users, as well as healthy adults placing bets, neuroscientists have found that the prospect of a reward activates the same circuits in the brain that the payoffs themselves do.
I am optimistic that the human race will continue to find ways of enhancing its own modes of thought, reason, and feeling. As flexible adaptive agents we are wide open to a surprising variety of transformative bodily and mental tricks and ploys, ranging from the use of software, sports regimes and meditational practice, to drug therapies, gene therapies, and direct brain-machine interfaces.
I am optimistic that, stimulated by this explosion of transformative opportunities, we will soon come to regard our selves as constantly negotiable collection of resources, easily able to straddle and criss-cross the boundaries between biology and artifact. In this hybrid vision of our own humanity I see increased potentials not just for repair but for empowerment, expansion, recreation, and growth. For some, this very same hybrid vision may raise specters of coercion, monstering and subjugation. For clearly, not all change is for the better, and hybridization (however naturally it may come to us) is neutral rather than an intrinsic good. But there is cause for (cautious) optimism.
First, there is nothing new about human enhancement. Ever since the dawn of language and self-conscious thought, the human species has been engaged in a unique 'natural experiment' in progressive niche construction. We engineer our own learning environments so as to create artificial developmental cocoons that impact our acquired capacities of thought and reason. Those enhanced minds then design new cognitive niches that train new generations of minds, and so on, in an empowering spiral of co-evolving complexity. The result is that, as Herbert Simon is reputed to have said, 'most human intelligence is artificial intelligence anyway'. New and emerging technologies of human cognitive enhancement are just one more step along this ancient path.
Second, the biological brain is itself populated by a vast number of hidden 'zombie processes' that underpin the skills and capacities upon which successful behavior depends. There are, for example, a plethora of such unconscious processes involved in activities from grasping an object all the way to the flashes of insight that characterize much daily skilful problem-solving. Technology and drug based enhancements add, to that standard mix, still more processes whose basic operating principles are not available for conscious inspection and control. The patient using a brain-computer interface to control a wheelchair will not typically know just how it all works, or be able to reconfigure the interface or software at will. But in this respect too, the new equipment is simply on a par with much of the old.
Finally, empirical science is at last beginning systematically to address the sources and wellsprings of human happiness and human flourishing, and the findings of these studies must themselves be taken as important data points for the design and marketing of (putative) technologies of enhancement.
In sum, I am optimistic that we will soon see the end of those over-used, and mostly ad hoc, appeals to the 'natural'...
Carlen et al. in Richard Davidson's laboratory at Wisconsin have used functional magnetic resonance imaging to examine: "whether individual differences in amygdala activation in response to negative relative to neutral information are related to differences in the speed with which such information is evaluated, the extent to which such differences are associated with medial prefrontal cortex function, and their relationship with measures of trait anxiety and psychological well-being (PWB)...faster judgments of negative relative to neutral information were associated with increased left and right amygdala activation. In the prefrontal cortex, faster judgment time was associated with relative decreased activation in a cluster in the ventral anterior cingulate cortex (ACC, Brodman Area 24). Furthermore, people who were slower to evaluate negative versus neutral information reported higher PWB. Importantly, higher PWB was strongly associated with increased activation in the ventral ACC for negative relative to neutral information.
Figure: Activity in the Ventral Anterior Cingulate predicts judgement time.
Figure: Activity in the ventral ACC in response to negative versus neutral images is positively associated with total PWB.
These findings suggest that people high in PWB effectively recruit the ventral ACC when confronted with potentially aversive stimuli, manifest reduced activity in subcortical regions such as the amygdala, and appraise such information as less salient as reflected in slower evaluative speed.
I've done some posts on defining happiness and how important social intimacy might or might not be. Several major magazines, including the Economist and the New York Times Magazine, have recently presented articles on research directed towards defining what happiness might in fact consist of, and a number of new university courses have the study of happiness as their main subject (see "Happiness 101, by D.T. Max). The distinction is frequently made between feeling good (the hedonic treadmill) and doing good. The former creates a hunger for more pleasure while the latter is suggested to be more likely to lead to lasting happiness.
My take on the fact that we frequently experience warm feelings after doing good is that we are experiencing the activation of our evolved affiliative neuro-endrocine repertoire, which has components like the release the neuropeptide oxytocin that promotes bonding and trust (see Feb. 13 post). There seems an obvious evolutionary rationale for the pleasure we take in helping others: groups of humans who develop this trait more highly might be more cooperative and effective in competition with other groups of humans whose members treat each other less sweetly. This, like all evolutionary psychology explanations, is hard to test or prove and thus criticized as pseudoscientific hand waving, but I like it. (There does seem to be a consensus that a major engine driving hominid evolution over the past several hundred thousand years has been competition between groups of humans.)
Such a group selection rationale can be applied also to why humans invent religions (which draw caustic blog posts from dry rationalists)...they wage war against other groups of humans more effectively. I do think David Sloan Wilson has it right on the central importance of group selection to human evolution. Have a look at his article "Testing major evolutionary hypothesis about religion with a random sample" which, along with several of this other recent interesting articles can be downloaded in PDF form from his website. I completely fail to understand the objection of the selfish-gene purists to group selection. Their points are now finding some refutation in mathematical models (cf. Bowles) that show how groups with altruistic genes might be better at waging war.
Why do citizens of Denmark have score higher than any other Western country on measures of life satisfaction? A brief article in today's Science section of the New York Times points to a study suggesting an answer: the country’s secret is a culture of low expectations. "...on surveys, Danes continually report lower expectations for the year to come, compared with most other nations... If you’re a big guy, you expect to be on the top all the time and you’re disappointed when things don’t go well. But when you’re down at the bottom .. you hang on, you don’t expect much, and once in a while you win, and it’s that much better....year after year, they are pleasantly surprised to find that not everything is getting more rotten in the state of Denmark,”
Rowe et. al. have measured the "effect of positive mood states ... in two different cognitive domains: semantic search (remote associates task) and visual selective attention (Eriksen flanker task). In the conceptual domain, positive affect enhanced access to remote associates, suggesting an increase in the scope of semantic access. In the visuospatial domain, positive affect impaired visual selective attention by increasing processing of spatially adjacent flanking distractors, suggesting an increase in the scope of visuospatial attention. During positive states, individual differences in enhanced semantic access were correlated with the degree of impaired visual selective attention. These findings demonstrate that positive states, by loosening the reins on inhibitory control, result in a fundamental change in the breadth of attentional allocation to both external visual and internal conceptual space."
More on mirror systems from Warren et al in Journal of Neuroscience. Edited clips from their paper:
Social interaction relies on the ability to react to communication signals. Although cortical sensory–motor "mirror" networks are thought to play a key role in visual aspects of primate communication, evidence for a similar generic role for auditory–motor interaction in primate nonverbal communication is lacking.
In this functional magnetic resonance imaging (fMRI) study, the authors investigated cortical regions responsive to both the perception of human vocalizations and the voluntary generation of facial expressions. In four auditory–perceptual conditions, subjects listened passively, without overt motor response, to nonverbal emotional vocalizations conveying two positive-valence emotions, amusement and triumph, and two negative-valence emotions, fear and disgust. Use of nonverbal, rather than verbal, vocalizations optimized recognizability of emotional content and avoided confounds of phonological and verbal content. In a facial movement condition, subjects performed voluntary smiling movements in the absence of auditory input. They hypothesized that cortical regions showing combined auditory–perceptual and motor responses would be located within premotor and motor cortical regions.
Figure legend: Brain regions demonstrating auditory–motor mirror responses. A shows regions (red) displaying a significant modulatory effect of emotion category on perceptual activation. B shows regions (light green) displaying significant activation during voluntary facial movements (motor > baseline). C, A masked inclusively in B shows regions (dark green) displaying both a significant modulatory effect of emotion category on perceptual activation and significant activation during voluntary facial movements.
Figure legend: Correlations with emotional valence and arousal in brain regions demonstrating auditory–motor mirror responses. Left, Regions (green) displaying both a significant modulatory effect of emotion category on perceptual activation and significant activation during voluntary facial movements as shown in the figure above. Right, Regions demonstrating a significant positive correlation between hemodynamic responses and emotional valence (red), emotional arousal (blue), or both (purple).
The authors demonstrated that a network of human premotor cortical regions activated during facial movement is also involved in auditory processing of affective nonverbal vocalizations. Within this auditory–motor mirror network, distinct functional subsystems respond preferentially to emotional valence and arousal properties of heard vocalizations. Positive emotional valence enhanced activation in a left posterior inferior frontal region involved in representation of prototypic actions, whereas increasing arousal enhanced activation in presupplementary motor area cortex involved in higher-order motor control. Their findings demonstrate that listening to nonverbal vocalizations can automatically engage preparation of responsive orofacial gestures, an effect that is greatest for positive-valence and high-arousal emotions. The automatic engagement of responsive orofacial gestures by emotional vocalizations suggests that auditory–motor interactions provide a fundamental mechanism for mirroring the emotional states of others during primate social behavior.
Motor facilitation by positive vocal emotions suggests a basic neural mechanism for establishing cohesive bonds within primate social groups.
Blanceflower and Oswald have done a fascinating study (PDF here) showing that across cultures, from Azerbaijan to Zimbabwe, we are happiest towards the beginning and end of our lives, leaving us most miserable in middle years between 40 and 50. For both men and women in the UK, the probability of depression peaked at around the age of 44. In the US, men were most likely to be unhappiest at 50, while for women the age was 40. The cause of the apparent U-shaped curve is not known. Quoting Oswald (the graphic is from his website):
1), such as the events that are occurring in the present, the thoughts we are having in the present, our present bodily states, and so on. We feel better when we imagine going to the theater than to the dentist, but we feel better imagining either event on a sunny day than on a rainy day, or when we are well rather than ill. Similarly, our future hedonic experience (H2) will be influenced both by our perception of the event (e2) and by contextual factors (
