In defense of humor.

Do you love to laugh? For decades, psychologists have studied the role of positive emotions in health and well-being. So far, it’s pretty clear that positive emotional experiences, including those that make you laugh, are related to better emotional and physical health. Yet, very few of those studies can make causal claims. In other words, they don’t really tell us whether healthier people seek out humor or whether laughter causes better health. Recently, Sarah Wellenzohn, University of Zurich, and colleagues set out to test the causal role of humor in the emotional health of individuals. In short, they designed an experiment to answer the question:  

Does humor increase happiness and decrease symptoms of depression?

To do this, they randomly assigned 632 adults to 1 of 6 interventions to complete daily for 1 week. The interventions were:  

Three funny things: Write down the 3 funniest things you experienced during the day and your feelings during those experiences.

Collecting funny things: Remember 1 of the funniest things you have experienced in the past, write it down with the most possible detail.

Counting funny things: Count all of the funny things that happen throughout the day and write down the number.

Applying humor: Notice the humor experienced throughout the day and add new humorous activities, such as reading comics, telling jokes, watching funny movies.

Solving stressful situations in a humorous way: Think about a stressful experience today and think about how it was or could have been solved in a funny way.

Early memories (placebo control): Write about early memories.

Before starting the intervention, participants completed questionnaires measuring their authentic happiness and symptoms of depression. Authentic happiness is measured using participant agreement to 24 statements such as “My life is filled with joy.”  Depressive symptoms include sad or low mood, loss of interest or pleasure, appetite and weight change, sleep problems, worry, difficulty concentrating, or feelings of hopelessness. Participants also received training in the intervention and were instructed to do their intervention activity each day for one week.

At the end of the 1-week intervention, and then 1-, 3-, and 6-months after completing the intervention, participants again completed the happiness and depression questionnaires. This enabled the research team to look at whether humor interventions led to increases in happiness and declines in depressive symptoms, and also look at how durable those effects are over time.

At the end of 1 week, all of the humor-based interventions were associated with increases in happiness and decreases in depressive symptoms compared to the placebo group. So one important take home message is that humor helps, no matter how you incorporate it into your life.

With respect to increasing happiness, Counting funny things and Applying humor were the most effective, and those effects lasted for up to 6 months! The effects of the Three funny things intervention also lasted through the 6-month time period, but were not as robust. There are a number of reasons that these humor-based interventions had such long-lasting effects on happiness. Most likely, it was because participants continued to engage in the behaviors for longer than just the initial week. Positive emotions are addictive in the same way food and drugs are. So it’s possible that these 1-week interventions were enough to promote a humor-addiction, so to speak.

The effects of these interventions on depressive symptoms were not as durable. Despite all of the humor-based interventions being leading to reductions in depressive symptoms at the end of the 1-week intervention compared with the placebo group, none of these effects remained 3-months after the intervention. This finding isn’t too surprising since there were no individuals with depression in this study. In fact, 250 people were excluded from the study for having elevated symptoms of depression at the baseline assessment. This means that there was very little range in depressive symptoms in the sample to begin with, and thus very little chance that the intervention could have an effect at all. That being said, humor on its own is unlikely to be an effective treatment for depression. Depression is an illness; often initiated in the wake of a major life stressor. With the exception of Solving stressful situations in a funny way, none of the humor-based interventions offered skills that help manage the source of that life stress.

The authors argue that one of the important, active ingredients in humor is the focus on increasing positive emotions in the present moment. Each intervention, particularly the durable ones, accomplished that through increasing daily experiences that involved humor but also increasing individuals’ attention to those experiences over time. You can imagine that just a few days of Counting funny things would cause you to pay more attention to, and enjoy, when funny things are occurring.

Until next time, keep on laughing! Here’s a compilation of funny videos of kids learning about physics: https://youtu.be/-TjtoP6-mcQ

Wellenzohn, S., Proyer, R. T., & Ruch, W. (2016). Humor-based online positive psychology interventions: A randomized placebo-controlled long-term trial. The Journal of Positive Psychology, 11(6), 584-594.

*Many thanks to Unsplash.com for the gorgeous photos. 

Who does the cleaning in your house? And why it matters.

With all of the #LeanIn and #HeForShe movements going on lately, division of housework has become a common topic of conversation. The typical family in the United States is comprised of two working adults, averaging about 91 paid hours (combined) per week. So, at the end of the work day, both adults are tasked with recovering from the work day, managing their home, and often caring for their children. Moreso than for any other generation, the division of housework matters. 

In 1965, women spent 30 hours per week devoted to housework while men spent about 5 hours per week. In the year 2000, the National Survey of Families and Households found that women spent about 18 hours per week doing housework while men spend about 10. This suggests a lot of things. First, the amount of hours the average family is spending on housework has declined by 20% since 1965, perhaps due to the introduction of time-saving technology such as microwaves, dishwashers, and washing machines into most American homes. It also says that as women have increasingly joined the work-force, men have increasingly participated in more housework. Yet, among households where both adults work full-time, men still report spending significantly more time "relaxing" and doing leisure activities after work, while women report spending more time doing housework and care-giving.  

Unfortunately, I find conversations about the division of housework to be mostly limited to issues of who does what and seldom about the potential consequences for health, wealth, and well-being. To me, the fact that men and women spend their time doing different activities is obvious and not very interesting. Whether the activities men and women engage in after work have implications for physical and psychological well-being interests me very much. Luckily these are empirical questions that psychologists care about and are actively trying to answer. 

In particular, Dr. Darby Saxbe, University of Southern California, and her colleagues asked the question: 

Does the division of labor in a household have implications for physical health in either partner? 

To answer this question, the research team recruited 30 healthy couples, both members working full-time, who own their own home, have a mortgage, and have at least one child between 8-10 years of age. With these participants, the research team tried to capture a "week in the life" of these couples by tracking their behaviors for 4 days from around 6:30-8:30am and then again from about 4pm to whenever the participants went to bed. Their goal was to capture what participants did before work, and after work. Tracking in this study constituted a research staff member recording each member of the household's location (e.g., kitchen, living room) and activity (e.g., cooking, watching TV) every 10 minutes into a handheld computer. Compared with previous studies that had used self-report assessments of how people spend their time at home, these observations allowed the research team to have a more objective measure of what participants' time at home looked like. 

Participants in this study also provided saliva samples on 3 days at waking, in the late morning (at work before lunch), afternoon (before leaving work), and right before bed. Saliva samples were used to measure the concentration of cortisol. Cortisol is final product of the body's physiological stress response system.* Cortisol in the body should be high in the morning and decline throughout the day. Not showing a steep decline in cortisol throughout the evening has been associated with poor sleep, several diseases, and is a predictor of mortality. In fact, many researchers see dysregulated cortisol as a pathway through which chronic stress leads to illness. The research team was interested in understanding whether the day-to-day activities of men and women at home were related to their body's ability to down-regulate this stress hormone in the evenings. 

They found that women were doing housework in 30.5% of observations, whereas men were doing housework in 20% of observations. In contrast, women were engaging in leisure activity in 10.6% of observations, whereas men were engaging in leisure activities in 19.4% of observations. Surprisingly, perhaps only for me, men and women were both engaging in communication in about 18% of observations. 

They then looked at whether activities at home predicted physiological stress in the evening. They found that both men and women who spend more time doing housework, have higher cortisol in the evenings. Perhaps more interesting, the amount of housework a wife does had no association with their husband's cortisol in the evening. In contrast, husbands observed doing more housework had wives with lower cortisol in the evening. 

When it came to leisure, husbands had lower cortisol in the evening when they spent more time doing leisure activities, especially when their wives were NOT engaging in leisure. In contrast, how much time women spent doing leisure activities was not related to their cortisol in the evening. 

So what does it all mean? The research team concluded creating a true division of labor at home may have real physiological benefits for wives, and suggested that these benefits (or the lack of them) can add up over time.         

So what's the solution? Perhaps it's that wives should make an executive decision to do less housework. A lot of households can accomplish this by making a decision to invest in their health by outsourcing housework to robots and third parties. My favorite examples of this are Roomba and Fluff-and-Fold laundry services. Perhaps it's that husbands need to make an effort to jump in when they see their wife doing housework. This includes, but is not limited to, cooking, vacuuming, doing laundry, dishes, changing sheets, and regularly scanning the house for stray belongings (read: socks). The good news is that many of these solutions are small but still make a big difference. 

This research study definitely doesn't provide all of the answers, and probably introduces more questions than it answers (as all good research does). For example, this study focused on heterosexual couples and therefore the role of "wife" vs "husband" is somewhat confounded with "male" vs "female." It's possible that women have higher physiological stress in the evenings than men, independent of housework. More studies looking at a more diverse sample of couples that include homosexual couples would help us understand how to disentangle the male-female differences from the role of housework-leisure behaviors. Also, this study only included couples where both parent works full-time. While this represents the average American family today, this study doesn't tell us much families with stay-at-home moms or dads.   

*Click here for past articles about/related to cortisol. 

Saxbe, D. E., Repetti, R. L., & Graesch, A. P. (2011). Time spent in housework and leisure: links with parents' physiological recovery from work. Journal of Family Psychology, 25(2), 271.

Many thanks to unsplash for the photos!

At risk for diabetes? Here's how to prevent it.

Psychology holds a strange position in modern medicine because we live in a time when everyone believes there is a pill that can solve their problems, and yet many common illnesses in medicine (e.g., pain, depression) are treated more effectively with behavioral medicine than pharmaceuticals. This week, I would like to share with you one of the original studies that showed us just how profound an impact psychologists and other mental health professionals can have on medical problems, specifically diabetes. 

American Diabetes Association

According to the CDC, 30 million people in the United States have diabetes. For more on diabetes from the CDC click here.  

In 2002, the Diabetes Prevention Program Research Group published the results of a 5 year study examining treatment outcomes for people at risk for diabetes. They asked the questions can you prevent diabetes? And what works: drugs or lifestyle change?

To answer these questions, they recruited 3,234 individuals who were at risk of diabetes based on their fasting glucose levels. These individuals were about 51 years old, 68% female, 45% belonged to an ethnic minority group, and the average BMI was 34 (BMI > 30 is considered obese). 

Each participant was then randomly assigned to 1 of 3 groups: placebo, Metformin, or Lifestyle change. The placebo group took 2 pills per day for the duration of the study. Metformin is the most commonly prescribed, 1st line treatment for Type 2 Diabetes. Participants in the Metformin group took an 850mg pill of Metformin twice daily for the duration of the study. 

Participants in the Lifestyle change group were assigned to a mental health professional who guided them through a 16-lesson curriculum in weekly, one-on-one meetings for 24 weeks. The goals of this program were to help the participant maintain 150 minutes of physical activity per week and reduce their body weight by 7%. By the end of the 24 week curriculum, 50% of participants had maintained the 7% weight loss and 74% of participants had maintained their physical activity regimen. After 24 weeks, participants continued to meet with their behavioral therapist monthly for the duration of the study in order to review and reinforce these lifestyle changes. 

To determine the effectiveness of these treatments, each participant was tested annually for diabetes using an oral glucose tolerance test. Over the next 5 years, the incidence of diabetes was 11% in the placebo group, 7.8% in the Metformin group, and 4.8% in the Lifestyle change group. In other words, Metformin was effective in reducing the incidence of diabetes by 31% whereas the behavioral Lifestyle change program was effective in reducing diabetes by 58%. 

Needless to say, these results caught the medical world by storm. First, no one really expected that behavioral medicine could be more effective than the gold standard medical treatment. Second, the world hadn't really considered how to leverage the power of mental health professionals in healthcare. Luckily, this was almost 15 years ago, and integrated primary care is becoming more commonplace. 

The WHO defines health as "a state of complete physical, mental and social well-being and not merely the absence of disease or infirmity," but we still have a long way to go. It seems as though many people still believe working with a mental health professional is only meant for extreme cases. Yet, these data are pretty clear that working with an expert in behavioral medicine, such as clinical psychologists, can be extremely effectively in maintaining health goals that going far beyond depression and anxiety. 

Diabetes Prevention Program Research Group. (2002). Reduction in the incidence of type 2 diabetes with lifestyle intervention or metformin. N Engl j Med, 2002(346), 393-403.

The Halo Effect

I've just finished reading Thinking Fast and Slow by Daniel Kahneman. Not exactly light summer reading, but still an engaging account of Dr. Kahneman's mental journey from wondering why humans are so bad at estimating the likelihood of events, to the development of some of the most important theories that explain human behavior. So important were these theories, in fact, that they won Dr. Kahneman a Nobel Prize, despite that it had never been awarded to a psychologist. As a psychologist, I was familiar with many of the principles explained in the book, but had never considered the cross-cutting value of them for marketing, law, medicine, public health, and beyond until I consumed them through his narrative.

What Kahneman does particularly well in this book is provide the research context under which his ideas developed. For example, he described the ideas and experiments put forth by his colleagues in psychology and economics departments around the world. One of those experiments was published by Richard Nisbett and Timothy DeCamp Wilson in 1977 at the University of Michigan (GO BLUE!) and is well known in psychology as the Halo Effect.

The Halo Effect has been around since 1920 when Thorndike coined the term, however until 1977 there was little empirical evidence to help us understand the effect. Simply, the Halo Effect describes how global evaluations of something influence our evaluations of specific attributes of that thing. So like good psychological scientists, Nisbett and Wilson sought to understand whether people are aware of Halo Effect when it is happening to them and the potential implications.

To do this, they recruited 118 undergraduate students. Half of the students saw a video-interview of a professor who presented himself as "as a likable teacher, respectful of his students' intelligence and motives, flexible in his approach to teaching, and enthusiastic about his subject matter." The other half of the participants saw a video-interview of the same professor who presented himself as, "quite unlikable, cold and distrustful toward his students, rigid and doctrinaire in his teaching style." After viewing the videotaped interview, the subjects rated the instructor's likability, as well as the attractiveness of his physical appearance, his mannerisms, and his accent from "extremely irritating" to "extremely appealing." In order to explore the question of subject awareness, some subjects were then asked whether the instructor's likability had affected their ratings of his appearance, mannerisms, and accent. Finally, participants were asked whether their rating of the professor on likeability influenced their ratings on his appearance, mannerisms, and accent.

They found that 70% of participants who saw the "warm and likeable" interview rated the professor's physical attractiveness as "appealing," while 70% of participants who saw the "cold and uninviting" interview rated the professors physical attractiveness as "irritating." A similar pattern was observed for ratings if his mannerisms, such that if he was warm and likeable, his mannerisms were perceived as appealing, while if he was cold, his mannerisms were irritating. This reminds me of the rose-colored glasses we wear when falling in love. Of course, it's endearing when someone you are falling for has cute little quirks, like saying "supposably," even though it drives your friends and family nuts. Even more interesting was that the professor in the interview had a thick, French accent. Participants who saw the video of the "warm" professor were equally likely to say the accent was appealing vs irritating, while participants who viewed the "cold" interview almost exclusively found the accent irritating. Important to note is that each of these attributes, physical attractiveness, mannerisms, and accent, were the same in both videos, what varied was the global impression of the individual as warm vs cold.

They also found that the Halo Effect depended upon a lack of awareness. Most people in the study reported that their global impression of the professor did not influence their ratings of his attributes, despite that it overwhelmingly did. This is good news though. The practical application of this important work is the knowledge that we will make global evaluations of others, and they will make them of us. The direct application of these findings to daily life are that if we are warm and friendly, people will find us more attractive and less irritating. So be warm and friendly, or at least try to be. The indirect application would be to recognize your global evaluations of people and things in the world, and practice interfering with your brain's tendency to spread those evaluations to other attributes incorrectly. For example, you can dislike a person, but they can still be good at their job.

At the center of Daniel Kahneman's work is the discrepancy between how economists believe rational people "should" behave, and how humans actually behave. The Halo Effect is alive and well in all of us, costs most of us a great deal of money, and likely prevents us from fostering relationships with great people in favor of not-so-great people.

Nisbett, R. E., & Wilson, T. D. (1977). The halo effect: Evidence for unconscious alteration of judgments. Journal of personality and social psychology, 35(4), 250.

Choose empathy.

Empathy is the capacity to understand or feel what another person is experiencing. The capacity for empathy is, above all, human. Empathy allows human beings to communicate and build societies, empathy is what allows parents to anticipate the needs of their children, and appealing to the empathic part of humanity is a powerful strategy for motivating behavior, such as charitable giving and activism. Psychologists have been studying empathy for decades. Is the capacity for empathy human? Are there some people who do not experience empathy? Are more empathic people more moral? More intelligent? More successful in their communities? And so on.

Generally, people agree that the capacity to take another's perspective, within which emotions are implicit, is innate. However, this innate capacity appears to have declined in recent history. But if empathy is innate, then what might explain the changes in capacity for empathy in society? These clues and questions led psychologists to wonder whether the capacity for empathy is malleable, and therefore can be incrementally developed, rather than fixed. This is an empirical question. In other words:

Does effort increase our capacity for empathy? 

To answer this question, Karina Schumann and colleagues at Stanford University conducted 7 studies that systematically tested empathy under conditions designed to disentangle whether people who believe that empathy requires effort will experience more empathy, as well as the consequences of those beliefs and effort. 

The first few of these studies aimed to simply test and then replicate whether believing that empathy is malleable is related to more empathy. It is. They found that individuals who reported beliefs that empathy was malleable, rather than fixed, also reported putting forth more effort and persistence in interactions with others. For example, people who reported that the capacity for empathy is malleable were more likely to strongly agree with statements such as, "When I disagree with someone, I try to understand their emotions," or "When I do not understand someone's feelings right away, I put effort into trying to understand them." So there was strong enough evidence that believing that empathy is malleable was related to the amount of effort people put into being empathic. 

The fourth study was my favorite, though. In this study, they wanted to know whether people could be primed to believe that empathy was either malleable of fixed, and whether that influenced their empathic thoughts and behaviors. To do this, they randomized 119 participants to either read a sham Psychology Today article about how empathy is malleable (can be cultivated), or a sham article about how empathy is fixed (doesn't change) within an individual. Next, participants were randomly assigned to imagine having a discussion with another person about an issue. The person is someone who holds the opposite view as them on an issue that the participant previously ranked as highly important to them, or unimportant to them. So to review, the participants ended up spread randomly across 4 groups:

1. Read an article about how empathy is malleable + disagreeing with someone about an important issue
2. Read an article about how empathy is malleable + disagreeing with someone about an unimportant issue

3. Read an article about how empathy is fixed + disagreeing with someone about an important issue

4. Read an article about how empathy is fixed + disagreeing with someone about an unimportant issue

They found that people in group 1 exerted more effort toward being empathic compared with group 3, suggesting that inducing beliefs about the malleability of empathy caused individuals to exert more effort to be empathic than those induced to believe it was fixed. Then they replicated this finding in experiments measuring different types of empathic, effort-related behaviors. For example, inducing people to believe that empathy is malleable led to more listening to another person's position in an argument, altruistic behavior, and making attempts to improve their empathic ability through online training. 

In short, this series of studies systematically demonstrated that believing empathy can be improved will cause people to use more effort to be empathic, which translates into more empathic behavior. Thus, the title of this article: choose empathy. Believing that empathy is flexible is the key. This has widespread implications in our society, from parents to teachers to the media. There appears to be a tendency today to assign people labels as empathic or not. I've seen people assign these labels to themselves, their children, politicians, and colleagues. Apparently, it is the belief that some people either are or are not empathic that holds us back. Hopefully, this article is a small step in changing that tendency. Instead, especially with children, we ought to be promoting the idea that our innate human capacity to take another's perspective and experience their emotions is a skill that can be practiced and even mastered, but it takes effort. 

Now, it is important to keep in mind that this study was conducted with presumably health adults who represent the normal population. Within clinical psychology, there are certainly clinical populations that are characterized by difficulty taking another's perspective or even the inability to experience empathy. So, as a clinical psychologist, I have to acknowledge that the findings of this article may not be universal, and that at the very least there are subpopulations where the effort necessary to experience empathy is greater. Even so, these sub-populations constitute less than 5% of the population, and more importantly no harm comes to this group by living  in a society where there is a expectation that empathy is a cultivated skill, requiring and worthy of effort. 

Now the real question is, how will you cultivate your empathy? Here are a few ways to start for both kids and adults. What's fabulous is that one of the best ways to cultivate empathy is through reading fiction. Yes, please! 

Schumann, K., Zaki, J., & Dweck, C. S. (2014). Addressing the empathy deficit: Beliefs about the malleability of empathy predict effortful responses when empathy is challenging. Journal of personality and social psychology,107(3), 475.

I hate exercise too.

Photo credit: https://unsplash.com/

I shouldn’t admit this because I am a health professional, but I don’t like exercise. Don’t get me wrong, I enjoy being active. I love living in a city because you can walk everywhere, hiking in the canyons with my dog, and I will usually take the stairs over the elevator to get from Point A to Point B. Despite generally enjoying living an active life, I really hate structured, overt exercise. I’m talking about the kind that requires you to buy a new wardrobe of workout clothes and visit a gym several times a week where you are strapped into machines that contort your muscles to-and-fro while someone who runs ultramarathons for fun yells “imagine carving out that panty line” and “get that leg a little higher” at you while you try not to cry or vomit. For me, all of this feels and seems completely ridiculous. That being said, the data consistently shows that engaging in 30 minutes of aerobic exercise at least 3 times per week will, literally, save your life. If you do that, you will live longer, get injured and sick less, spend less money on medical bills, look younger, feel happier, and sleep more restfully. As far as investments go, exercise is a safe bet. So, professionally, I make recommendations that people exercise, like I did here, and I also participate 2 hours per week in the Los Angeles cult that is CardioBarre. For better or for worse, it is the nearest to my house.

But sometimes, despite this laundry list of benefits, I find it difficult to muster up the motivation to engage in overt exercise activities. There are so many hours in the day, and just under a million other things I could be doing instead that would feel more productive or that I would actually enjoy. If there is anyone out there who thinks and feels the same way, this post is directed at you. In fact, only 26% of people in the United States actually meet the recommended weekly exercise dose, so this is directed at most of you.

In 2008, Hillman, Erickson, and Kramer published a review of what we know about the effects of exercise on the brain. While they reviewed the results of many findings, I will limit my explanation to 3 findings that are particularly motivating for me. First and foremost, exercise creates new brain cells. If you have two cages of rodents, one cage with a running wheel, and one cage without, the rodents in the cage with the running wheel will run on it and create new neurons. Throughout your life, you are creating and losing neurons, with an imbalance toward creating in the first half of life and an imbalance toward losing in the second half. However, exercise promotes the creation of new neurons, thus allowing for more learning early in life, and less deterioration in later life. Second, exercise makes daily tasks less difficult. If you have older adults (ages 60-85) participate in aerobic training multiple times per week over several months, they will process information more quickly, have better spatial reasoning, and have much better executive functioning than people who did not participate in the exercise program. Executive functioning skills most robustly improved compared with the control group as a result of exercise, which include complex thinking such as planning, problem solving, holding multiple pieces of information in memory, and switching between tasks. These results are actually so convincing that researchers are looking into whether exercise interventions can prevent or even reverse the effects of Alzheimer’s Disease. Stay tuned for more on that in the future. Finally, exercise makes you smarter. These effects can even be intergenerational. For example, mothers who exercise during their pregnancy have offspring with more brain cells in the parts of their brain responsible for learning and memory (hippocampus & dentate gyrus). As children continue to develop, kids who engage in more physical activity have higher IQs, better achievement scores in both verbal and math assessments, and have better memories.

So there you have it, even if it’s silly and feels like a sweaty, waste of time and money, exercising with regularity will put you in a better mood, help you think more clearly while you work, and will continue to promote your ability to learn (whatever you want) throughout your life. When you put it in perspective like that, 30 minutes every couple of days isn’t so bad.


Hillman, C. H., Erickson, K. I., & Kramer, A. F. (2008). Be smart, exercise your heart: exercise effects on brain and cognition. Nature reviews neuroscience,9(1), 58-65.