Stress can be contagious—and scientists want to learn more about it

Fear (and stress) can be contagious via pheromones secreted by the body

While seeing someone else in a panicked state may induce a stress response, researchers have found stress can be literally contagious—chemicals contained in sweat and other secretions can trigger stress hormone release in others. Theories suggest this feature is an evolutionary adaptation to protect groups from danger.

Stress evolved as a survival mechanism to keep humans alive

Stress activates the “fight-or-flight” response when we face threats. It’s triggered by the hypothalamus, which signals the release of adrenaline and cortisol, heightening awareness and energy. While acute stress helps in short bursts, chronic stress—persistent over time—can harm both physical and mental health, leading to conditions like hypertension, anxiety, or depression.

Too little stress can be as problematic as too much stress

Hormesis—mild or moderate stress followed by recovery—helps make us more resilient. A stress expert speaking during this roughly 30-minute CNN special explains that our bodies depend on periodic mental and physical challenges to activate our innate defense mechanisms, spurring cellular repair and regeneration.

How we frame stress—as good or bad—seems to alter how it affects us

This podcast discusses research that indicates stress perception may drastically affect how we respond to it. In research exploring if our stress is presented as diminishing our health versus if we're told it enhances our performance, it will lead to differences in how successful participants are at performing tasks—with the enhancers doing better.

The positives of feeling stressed

Worrying about past events and upcoming challenges is not a pleasant experience, but a reasonable amount of stress can bring a lot of good into our lives. In this episode of "The Happiness Lab" with Dr. Laurie Santos, two psychology experts offer tips for resetting one's relationship with stress. Listen and learn how to make stress a positive tool rather than a debilitating emotion.

How stress affects every organ in the body

If you are a visual learner, this resource is for you. Not only does this article from the World Economic Forum outline the causes of modern stress along with helpful strategies, but they have created an approachable infographic to show exactly how stress manifests throughout our different bodily systems. Pair this visual guide with our other resources to gain a deep knowledge of stress and the human body.

Stress affects different animals in different, but useful, ways

Animals feel stress when they experience actual dangers—such as a zebra chased by a lion. Humans often feel stress from worries, memories, or even thoughts about problems that may occur in the future. For this reason, animals tend to experience stress in short, intense bursts. Conversely, people can feel stressed for long periods, which can eventually be harmful to their health.

How burnout alters your brain

Stress is a normal part of everyday life, and it’s not necessarily all bad. But chronic stress—the kind that leads to burnout—can change the size and functioning of parts of your brain. It can alter the ability to make new brain cells and memories and even potentially modify your DNA.

What employers can do about parental stress

The US Surgeon General recently released a formal warning deeming parental stress a public health issue. The advisory also included recommendations for how employers can mitigate the issue. Employers can help their employees access child care, for instance, or provide flexible working hours. To find out more about what the Surgeon General prescribes, read more here.

Humans are wired to pick up on each other's emotion, making laughter contagious

The reaction plays a key role in establishing interpersonal connections and relieving stress by releasing endorphins—feel-good hormones. A 2021 study identified at least 65 animal species that produce playful sounds, such as laughter.

Consuming true crime media can increase stress and anxiety

Consuming true crime media can activate one's sympathetic nervous system, which controls the fight-or-flight response. Staying in this heightened state of vigilance can lead to stress-related illnesses, including hypertension, and mental conditions, including depression and anxiety. Additionally, people who actively consume crime news, whether they consider it to be entertainment or educational in nature, report being more fearful of crime, regardless of actual crime rates.

Short-term cortisol spikes can boost the immune system

Elevated acute levels can enhance the immune system's ability to fight off infection or respond to injury. Chronic heightened cortisol levels, however, can lead to inflammation that harms cells and tissues over time.

Some claim breathwork can improve mental health, help process trauma, and more

Research shows people who practice breathing exercises see a decrease in depression and stress levels, and that such exercises are about as effective at treating PTSD as conventional approaches. Even something as simple as extending exhales can slow one's heart rate and activate the parasympathetic nervous system.

How artificial intelligence, which detects patterns, can identify burnout

Researchers are training AI to detect stress-related symptoms, helping physicians and other medical workers recognize and reduce stress from overwork and potentially avoid burnout.

The science of spring fever

Researchers have confirmed what people have sensed for ages: Our emotions during the springtime can go a little wild. This piece breaks down the impact of the seasonal transition on our bodies and prescribes a few ways to mitigate the effects.

Can the gut microbiome influence personality?

New research suggests the bacteria in our gut—through the hormones and molecules they produce—can contribute to conditions ranging from depression to anxiety, and much more. The findings suggest diets have a direct impact on mental health and may lead to new therapies.

Some argue that investment banking could be a health hazard

Back in 2012, a University of Southern California researcher published a decade-long study in which she observed investment bankers’ health. The results weren’t exactly stellar. Every individual the researcher observed developed a stress-related physical or emotional ailment within several years of working in investment banking.

Researchers are studying roller coasters to improve mental health treatments

Scary rides stimulate our fight-or-flight response while simultaneously releasing feel-good endorphins like dopamine, serotonin, and oxytocin. Once we realize we're in a safe space, we can enjoy the ride and even feel confident and relieved by the accomplishment of overcoming a fearful feat.

Explore how cells respond to signals from their environment

In "Dropping Signals," users can drag stimuli, such as hormones and light, into various cellular environments to observe cellular responses. These include changing their shape, enabling the transport of chemicals into or out of the cell via the cell membrane, or dividing to compensate for surrounding damaged cells.

The neuroscience of heartbreak

An analysis of functional MRIs revealed a difficult fact: the active brain areas of people experiencing heartbreak were very similar to those actively in love. This is a major reason why people in the middle of rejection can't accept the reality of their loss. This article breaks down the various changes in neurotransmitters and neural pathways for those enduring that universal experience, heartbreak.

The science of food allergies

Why do certain substances trigger an immune response while others don't? Listen to researchers explain the science in this five-minute video. Food allergies affect around 8% of children and 2% of adults in the US, and—unlike sensitivity or intolerance—they involve the immune system mistaking certain harmless proteins in foods as dangerous invaders, triggering a rapid and sometimes severe defense response.

Eating competitions can ruin a stomach's elasticity

Competitive eaters make room for all that food by toying with the stomach's ability to expand and contract. Still, doctors warn that repeated stress can destroy that ability, leading to further issues.

Most things you would get tested for at the doctor’s office are influenced by circadian rhythm

In this video, a Salk Institute Researcher offers daily habit tips focused on aligning with your circadian rhythms. She notes heart rate and blood pressure are highest in the afternoon, for example, and there’s a triglyceride peak in the morning. Generally, she says, it’s a good idea to schedule your doctor’s checkups at the same time of day each year so there’s consistency across your data.

73% of people report they crave more physical touch in their lives

This figure came from a 2019 survey of 110 adults and examined what's formally called a "touch gap." Touch helps reduce stress, strengthening our immune system, and overall well-being. It can also improve children's health, adjustment, and IQ scores.

The scandal that rocked stem cell research

In 2014, a Japanese research group published a paper suggesting ordinary cells could be reverted to pluripotent stem cells by subjecting them to external stressors. The results generated interest but could never be replicated. The lead researcher was accused of fraud, and the group’s supervisor committed suicide.

In recent years a child anxiety expert has created and tested a novel phobia and anxiety treatment approach for children, focused on changing how parents respond to the fears.

Watch how viruses like Ebola can spill over from animals to humans—and vice-versa.

Studies suggest when you sleep is as important as how much you get, and syncing with your circadian rhythms may lead to less fatigue and improved long-term health outcomes

Learn how your body is, scientifically, like a firework with its own slow, controlled burn.

Scientists testing how climate change affects plants found, in a years-long simulation study, that poison ivy grew 70% faster with the resulting extra carbon dioxide.

Astronauts have repaired genetic damage in space using CRISPR—a molecular tool that can make precise changes to DNA and is used in single-celled organisms to attack invasive viruses.

Hookworm infection, though risky, may help fight certain autoimmune conditions by tamping down the immune system's inflammatory response.

Fear or disgust related to clusters of holes and cracks, called trypophobia, may stem from evolutionary processes to help us avoid pathogens.

Explore an interactive map built from more than 100,000 survey responses on where people find joy in their lives

Alzheimer's can lead to brain shrinkage, with an average of around 2% of volume reduction per year

Listen to an in-depth conversation on the links between Parkinson's disease and herbicide exposure and the challenging pace of scientific investigation.

After 25 people used virtual reality headsets to practice flying with virtual wings—flapping their arms—their visual cortex responded to the wings almost as if they were real arms, treating them as body parts.

Chaos theory—informally known as the butterfly effect—is the reason why weather forecasts are presented with probabilities rather than certainties.

Fast-casual restaurant Chili's is experiencing a resurgence, with its parent company recently reporting a nearly 32% increase in sales, thanks to passionate Gen Z fans on TikTok.

At the beginning of the 20th century, a group of young men ate standard American food—replete with food additives like borax and formaldehyde—as part of government research to better understand food safety.

Fish populations in the Great Barrier Reef have increased after installing waterproof speakers on the ocean floor that played recordings of sounds from healthy coral reefs.

Play the role of a student in a game where you try to navigate college and remain debt-free, selecting different income levels, high school experience, race, ethnicity, and more.

Clever Hans was a 1900s horse that was believed to be able to solve math equations, tell time, and read and comprehend German, until a psychology student discovered how he got his answers.

US consumers collectively owe more than $1T to credit card companies—almost as much as they owe in auto loans.

Existentialist writer Jean-Paul Sartre coined the famous phrase 'Hell is—other people' in his play 'No Exit'

Explore the known asteroids, comets, and spacecraft involved in asteroid studies within our solar system with 'Eyes on Asteroids,' a 3D visualization from NASA.

As of 2025, the most cited papers in science include a review of graphene, methods to improve image recognition, streamlining electron density calculations, and optimizing protein studies.

Some Pokémon have been named after real and fictional organisms, while some real-world species have been named after Pokémon, such as Chilicola charizard and Binburrum zapdos.

While the sun's gravity keeps the planets in orbit, their gravity also pulls on the sun, causing it and everything else in the solar system to orbit around a mutual balance point called the barycenter—the true center of the solar system.

Learn how to read a prospectus, the juicy document that any company must file with the SEC before going public.