The Wall Street Journal Column

In fact, researchers have found that placebos can be effective even when they are “open.” Surprisingly enough, taking a sugar pill can be beneficial even when you know it’s a sugar pill. Now a new study published in Nature Scientific Reports last December shows that open placebos don’t just work for physical pain; they can also reduce negative emotions like guilt.

Led by Dilan Sezer, a doctoral student in clinical psychology at the University of Basel, the study recruited 112 healthy university students between 18 and 40 years old. “Then there was a baseline assessment of their guilt. Using a questionnaire, we asked, how guilty do they feel in general?” said Ms. Sezer.

At the next stage of the study, people were asked to write about a specific event in their past that made them feel shame for having treated someone shabbily, and the strength of their guilty feelings was assessed with a questionnaire. Then the participants were randomly assigned to one of three groups. The first was given a “deceptive” placebo: It contained no medicinal ingredients, but participants were told it contained herbs and essential oils that had been “shown to reduce guilt feelings.” The second group was given an “open” placebo and were told that it “does not contain any medicinal ingredients.” The third was a control group that received no intervention at all.

Afterward, each participant was asked to fill out the same questionnaire a second time. The findings were crystal clear: Both placebo groups showed a significant drop in guilt compared to those in the no-treatment control group. What’s more, “the difference between placebo groups was statistically indistinguishable,” Ms. Sezer said.

How can placebos work when a person knows they’re fake? Some researchers have speculated that a combination of hope and uncertainty leads the “brain to anticipate, seek out and identify new data or rewards,” writes Ted Kaptchuk, who leads the Program in Placebo Studies at Harvard Medical School. The human brain is constantly testing hypotheses about what might come next, even if we are not overtly aware of this process. Certain environments and rituals also create expectations about how we are going to feel, whether we’re seeing a play in a theater or participating in a study in a lab or clinic.

Ms. Sezer’s study reinforces the notion that we aren’t always completely rational about what can help us. She notes that her sample was small and included only psychologically healthy people, but she hopes the findings will be investigated further. “We don’t know yet if this will work in a clinical population,” she says, “but for everyday guilt in young people, it works.”

Now, in a science-imitates-art moment, a 20-year-long study has been published in the journal Developmental Psychology that charts the lives of a much bigger sample: 3,000 randomly selected Americans between the ages of 22 and 77. Each subject participated in three interview “bursts,” in 1996, 2005 and 2017, in which they talked to researchers every day for eight days. The goal was to map out the number of stressful events participants faced at each stage of life and how they reacted to these challenges.

“One of the things I really appreciate is the value of talking to someone about their day, just hearing their voice, every night for eight consecutive nights,” said David Almeida, a professor of human development at Penn State University, who has led the study since the beginning. “We really wanted to capture the ebb and flow of daily life as it was happening.”

The researchers found that stress drops steadily as we get older. Life is particularly fraught in young adulthood, when we face more stressful situations and have fewer psychological resources to deal with them. By the time we reach our 40s and 50s, our emotional lives tend to settle down. While this period is often portrayed in popular culture as a time of midlife crisis, divorce and career upheaval, the researchers state that “our findings reveal a clear and robust benefit with age.”

The researchers offer an explanation for this pattern. Young adulthood is marked by numerous transitions: graduating from college, finding a job, navigating financial independence, getting married and having small children. “Younger adults have more strain, more role conflict. But by midlife you’re more established in your career, and your children are growing up,” said Dr. Almeida.

Another explanation, he added, is that “When we don’t have as much life left, we want to maximize the time we have.” We’re more motivated to avoid jerks and futile conflicts. Finally, by midlife we have more experience in solving problems. “When I was younger, I would freak out if I had a plumbing problem,” Dr. Almeida said. “But now I know a plumber I can call.”

Stress is a biochemical reaction that evolved to help keep human beings alive when we were hunters and gatherers. Now that most of us work in cities, why is it still with us? “We’ve done a series of studies searching for its benefits,” Dr. Almeida explained. “One shows that stress forces you to solve novel problems; people who experience more daily stress also perform better on cognitive tasks.”

What’s more, on stressful days people tend to have more social contact. If you have a problem and call up your friend, she can’t necessarily provide a solution, “but you get the social support that you need to deal with it,” said Dr. Almeida. The benefit of that social interaction, especially in young adulthood, seems to outweigh the angst of stress.

That question sparked a remarkable study published this month in the Proceedings of the National Academy of Sciences. Lead author Elizabeth Dunn, a professor of psychology at the University of British Columbia, along with her doctoral student Ryan Dwyer, knew from prior research that there tends to be a correlation between receiving a sum of money and being happier. But those studies didn’t untangle the direction of causation—whether happier people made more money, or whether money made people happy.

The opportunity to dig deeper fell in their laps in 2020, when two anonymous donors offered to give Chris Anderson, the CEO and chief curator of TED, $2 million to distribute to worthy individuals around the world. Mr. Anderson then contacted Prof. Dunn. Might she be interested in studying the impact of these gifts? “Hell, yeah,” she answered.

After weeding out those whose lives might be endangered by a sudden influx of cash, the study ended up with 300 participants. Two hundred were randomly chosen to receive $10,000 via PayPal. The remaining 100 respondents served as the control group. All participants had completed a baseline survey about their psychological well-being and annual earnings at the beginning of the experiment, then completed follow-up surveys one, two, three and six months after the cash was distributed. Members of the control group received $25 each time they filled out a survey.

The researchers found that, as might be expected, a big windfall made people happier than the drip-drip-drip of repeated $25 gifts. But the money didn’t have the same effect on everyone. “The gains were greatest for recipients who had the least,” the paper found. People in lower-income countries who received $10,000 gained three times more happiness, based on the self-reported surveys, than those in higher-income countries. For recipients whose annual income was $100,000 or above, the gain in happiness was diminished.

Comparing participants in the same country, those who made $10,000 a year gained twice as much happiness from the windfall as those making $100,000 a year. “This is consistent with a mountain of research showing that the more we have of something, the less we feel about increases. Those with lower income get a better boost,” said Prof. Dunn.

In 2021, four billion people worldwide lived on less than $6.70 a day. The new study suggests that if any of them got a cash gift with no strings attached, a smile would likely appear on their face. Perhaps such giving should become a Thanksgiving tradition, along with turkey and football. “My fondest wish is that people will emulate what this couple did,” said Prof. Dunn. For people who have money to spare, giving it away creates “more happiness than if you kept it for yourselves.”

Can dogs smell something as ineffable as psychological distress? Mood disorders have surged since the onset of the Covid-19 pandemic and the demand for emotional support dogs has followed suit, with customers paying anywhere from $15,000 to $50,000 for a dog trained to respond right before a panic attack, or when the owner’s PTSD or addictive cravings bloom. Until recently, evidence that dogs can sniff out our psychological states remained anecdotal. “The assumption that dogs can identify a person’s psychological state is the reason why we have service dogs for PTSD, anxiety disorders and depression,” says Clara Wilson, a researcher at the Animal Behaviour Centre at Queens University Belfast. “It seems so obvious that no one has tested the idea empirically. Until now.”

In a study published in September in the journal PLoS One, Ms. Wilson and colleagues tested whether dogs can read and respond to our emotional states, without the benefit of facial expression, tone of voice, or social context. The researchers trained four dogs to detect and react to the smell of human stress, depending on their sense of smell alone to distinguish between a person’s baseline scent and the unique cocktail of volatile organic compounds (VOCs) in their sweat and breath when they’re feeling stressed out.

Using tasty rewards, the researchers trained the dogs to distinguish between three gauze samples. One was neutral, containing no human scent. The second had been breathed on and then wiped across the back of the neck of one of 36 human participants at a moment when they felt completely relaxed. The third set of sweat-and-breath samples was taken before and after the participant completed an arithmetic task under time pressure. The humans’ heart rate and blood pressure were monitored, to confirm that the smell of the gauze was indeed a sign of stress.

The goal was to teach the dog to pick out the “stress” sample from a set of three swatches and indicate it by sitting up in front of that sample, alert and attentive. To avoid giving the dog any inadvertent visual or social cues, each swatch was presented behind a grill, so it couldn’t be seen or touched, and no humans were present during the test. If the dog could pick out the stress sample from the distractors, he or she was rewarded with something good to eat.

Appeared in the October 22, 2022, print edition as ‘Dogs Can Sniff Out When a Human Is Stressed’.

Evidence is building, however, that older fathers also share some risk. Sperm cells generated later in a man’s life are more likely to feature genetic mutations that can lead to developmental disorders in children.

“There is evidence in humans that paternal aging is one of the risk factors for autism and other neurodevelopmental disorders,” said Noriko Osumi, a professor of developmental neuroscience at Tohoku University in Japan. “But there are a lot of confounding factors in humans. Is paternal aging itself really the cause, or is it something else?”

A new study led by Prof. Osumi involving newborn mice sheds light on the question. The study shows that mouse pups with older fathers are smaller and cry differently than those with younger dads. This can have negative consequences for the babies, she explained on a video call: “Some other [research] groups have noticed that if the baby’s type of cry is different, then the mother’s retrieval pattern changes.” A weird cry may mean that the mother isn’t primed to respond to the baby’s calls, in other words.

The research team, which includes first author Lingling Mai, a doctoral student in neuroscience at Tohoku University, included 120 mice. Half had fathers who were 3 months old, the equivalent of a human baby having a father in his 20s, while the other half had fathers between 1 and 2 years of age, comparable to having a human father in his 50s or 60s.

The mouse pups in the two groups were then separated from their mothers and littermates four times, at 3, 6, 9 and 12 days old. Each time the pups were placed in the “separation box,” their distress cries were recorded and analyzed. Under ordinary circumstances a human ear can’t hear these vocalizations, so the research team used special equipment and software to translate and graph the sound patterns, including downward or upward shifts in tone, harmonics, phrase repetitions and octave jumps.

A comparison between the two groups revealed that mice with young fathers were far more likely to have rich and complex cries than those with older fathers. The patterns of sound they emitted were also more likely to resemble each other. In comparison, the pups with older fathers cried less overall. Their vocalizations were more variable, yet had a more limited repertoire of sounds.

The study also found that pups with older fathers weighed less, which I expect may be related to the way they communicate. An animal with a sporadic, weak cry is likely to attract less attention from its mother, so it would nurse less and gain less weight.

Appeared in the September 17, 2022, print edition as ‘The Risks of Having an Older Father’.