# Behind a smile: what science says about smiling

Smiling helps regulate stress and can lift your mood, but the gesture does not mean the same thing in every culture. And in babies, laughter arrives before speech.

- Section: Longevity
- Published: November 13, 2026
- Address: https://ceoone.com.br/en/article/behind-a-smile-what-science-says-about-smiling
- Em português: https://ceoone.com.br/artigo/por-tras-de-um-sorriso-o-que-a-ciencia-diz-sobre-sorrir.md

![Illustration of four smiling mouths with legs, parading among flowers on a cream background](https://pub-b80e49b2737940b3ab5d3f20d0578192.r2.dev/artigos/por-tras-de-um-sorriso-o-que-a-ciencia-diz-sobre-sorrir-foto.webp)

Produced by AI

## Key points

- Smiling can reduce aspects of the body's stress response and influence mood, experts say.
- Smiles are not read the same way in every culture: in East Asia a broad smile may seem untrustworthy.
- In babies, laughter appears before speech and signals that it is safe to explore and bond.

Remembering to smile often can help you make friends and also make you feel better. Instead of waiting for a reason, simply swapping a frown for a smile can affect your emotions, experts say. Recent research suggests the gesture makes a difference.

Older studies focused on the facial feedback hypothesis, says Jeanne Tsai, a psychology professor at Stanford University and director of its Culture and Emotion Lab. In a classic experiment from the late 1980s, participants held a pencil between their lips to force a smiling or a displeased expression while watching a cheerful film clip, such as a cartoon. Those who smiled felt the sensation of the smile more and enjoyed themselves more.

"When we do this demonstration in class, it works," Jeanne says. "When you do it alone, it's not a social interaction; maybe it leads you to recall something, a positive event, which ends up putting you in a good mood."

## Health benefits

Judy Ho, a clinical and forensic neuropsychologist in Los Angeles and a professor at Pepperdine University, treats smiling as a coping strategy for some patients with depression or anxiety. "I'm not suggesting this is the only way to solve things. It's just one more tool you can add to your toolkit."

According to her, smiling can affect levels of cortisol, a hormone released partly to regulate stress, and mood. The gesture can also influence neurotransmitters associated with positive feelings, such as endorphins, dopamine and serotonin. "People who smile during stressful tasks generally have lower heart rates during recovery than those who keep neutral expressions," she says. "Smiling also reduces aspects of the body's physiological stress response." The hope, she says, is that if you smile enough, you begin to feel it inside. "In a way, it's like a mediating effect."

In California, a group of charter schools in Orange County takes smiling seriously: a whole section of its website is devoted to the idea that smiling creates a welcoming classroom, with relaxed, active and motivated students. "I have always believed school should be a happy place for children," says RaNae Posey, principal of one of the schools. "To help them build the habit of seeing the bright side of things."

## Cultural differences

How a smile, and the sincerity behind it, is perceived is not universal. Jeanne Tsai has studied how American culture values the constant pursuit of positive feelings and plays down sadness. In East Asian cultures, emotion is more about balance. "It's as if positive and negative emotions were intertwined, so you don't want to feel too positive or too negative. You're looking more for a balance between the two."

In her studies, European Americans and East Asians, including Taiwanese, South Koreans, Japanese and Hong Kong Chinese, rated facial expressions for warmth and trustworthiness. While Americans found enthusiastic smiles the friendliest, some Asians saw them as emotionally unstable or untrustworthy. "The type of smile matters: whether it's a calm, closed-mouth smile, more like the Dalai Lama's, or a broad, enthusiastic, toothy smile, like Julia Roberts'," she says. In studies in Taiwan, for example, the open smile is not appreciated unless it really suits the situation.

In Thailand, known as the land of smiles, the gesture is rooted in the culture: there are about 30 Thai words for smile. Many programmes that place English teachers in the country advise that smiling often at children and colleagues is essential to show respect, good manners and calm.

![Illustration of a large smile shaped like a crescent moon, with small figures of all ages resting and playing on it](https://pub-b80e49b2737940b3ab5d3f20d0578192.r2.dev/artigos/por-tras-de-um-sorriso-o-que-a-ciencia-diz-sobre-sorrir-crescente.webp)

Shared laughter signals an emotional bond from the first months of life. Produced by AI

## Smiling without pressure

In recent years, women have pushed back against the idea that they must smile at work while men need not. Smiling can feel like a paradox for some women and sometimes for Black people, who may be stereotyped as unapproachable or cold if they do not smile enough. Last year the retailer Target was mocked on social media for introducing a smiling policy: staff had to smile and make eye contact with customers within about three metres and greet them within 1.2 metres.

According to Nicholas Coles, head of the Social Sciences Lab at the University of Florida, people dislike the feeling of losing emotional autonomy. "In those scenarios, what we see is that you actually end up walking towards unhappiness while you smile," he says. For him, the real effect only appears when the smile is authentic and spontaneous. With the holidays approaching, many people will have to force a smile at family gatherings when delicate topics such as politics and religion come up, which may be a good chance to test the effect. "If we could simply smile and think 'look, this is someone who cares about me and loves me', maybe that would change how we react to them, even in a difficult conversation," says Judy Ho.

## Laughter comes before speech

Far more than a sign of joy, children's laughter helps with learning, memory, emotional regulation and stress control. It appears before speech and helps babies connect emotionally with the world in their first months, because the brain structures linked to emotion mature before the areas responsible for language, explains neuropaediatrician Leticia Sampaio, of the Children's Institute at the University of São Paulo's Hospital das Clínicas.

In childhood the brain develops intensely, and laughter works as a signal that it is safe to explore, learn and connect, according to Jacqueline Harding, an early childhood specialist and researcher at Middlesex University in the United Kingdom. For her, humour is a kind of biological glue in human relationships. "Playful moments allow children to release tension safely while staying connected to caring adults."

Psychologist Maria Beatriz Linhares, a professor and researcher at the University of São Paulo and a member of the Science for Childhood Nucleus, notes that shared laughter signals emotional bonding and security. Beyond emotional attunement, children experience being welcomed and connected with those who care for them. These exchanges, she says, help build that bond as a secure base for human development.

## Sources and editorial notes

- Based on O Estado de S. Paulo, November 7, 2026 edition, Pulsa section, pages D4 and D5: report by Terry Tang, of the Associated Press, and article by Andressa Lima.

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