The Science Behind Laughter: Why Do We Find Things Funny?

Laughter is a peculiar phenomenon that affects our bodies in various ways. When we laugh, our abdominal muscles contract, altering our breathing patterns and causing increased pressure in the chest cavity. Laughter also inhibits reflexes and muscle control, potentially causing sensations like leg weakness. While it is unclear exactly how and why laughter evolved, scientists have observed similar behaviors in other animals, suggesting a common origin. Laughter likely originated as a signal of friendly intent during play, but evolved in humans to convey a range of emotions and enhance social interactions. Additionally, laughter has been linked to the release of feel-good neurotransmitters and improved overall health.

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How does this happen?

Key Insights:

  • When we laugh, our abdominal muscles contract rapidly, causing changes in breathing patterns and increased pressure in the chest cavity.
  • Laughter can result in vocalizations like snorts, wheezes, or other audible sounds.
  • Laughter can lead to sensations of muscle pain or weakness, inhibiting reflexes and muscle control.
  • Rats and many other mammals and birds also vocalize during social play, suggesting laughter-like behavior is not unique to humans.
  • Laughter may have evolved as a way to signal friendliness and non-aggression during play.
  • Humans have expanded the use of laughter beyond play, incorporating it into speech to convey emotions and meaning.
  • Laughter is contagious and can trigger smiles or laughter in others.
  • Human laughter can be louder and serve as a broadcast to everyone around.
  • Laughter triggers the release of feel-good neurotransmitters and reduces stress hormone levels.
  • Laughing may help cope with stress and improve cardiovascular health.


Isn’t it strange that when something is funny, we show our teeth, change our breathing, feel weak or achy in certain places, and sometimes even cry? In other words, why do we laugh? Well, when you laugh, your abdominal muscles contract rapidly, which affects your breathing and increases pressure in your chest cavity, causing air to be pushed out, resulting in audible sounds such as snorts, wheezes, or vocalizations. Since your abdominal muscles are worked more than they typically would be while talking, they can start to hurt. Additionally, laughter can have an impact on your reflexes and muscle control, leading to sensations like weakness in the legs. But where does this strange phenomenon come from? While there is no archaeological evidence of laughter, scientists have some theories. Importantly, laughter is not unique to humans. Researchers discovered, using ultrasonic recorders in the late 90s, that rats essentially giggle when tickled. Since then, evidence has been compiled of at least 65 species, mostly mammals but also some birds, that vocalize during social play. Some of these species are our closest relatives. By studying the sounds primates make while playing and being tickled, researchers have become more convinced that laughter-like behavior existed in the ancient ancestor of all great apes. Furthermore, since other apes also make laughter-like sounds during rough-and-tumble play, it is suggested that laughter may have originally evolved as a clear signal of friendly intent. However, humans don’t just laugh during play but also when amused, surprised, confused, or nervous. Some scientists believe that laughter expanded its functions after humans diverged from other apes, as we developed large social groups and more complex language abilities. They hypothesize that laughter gradually became a means to convey subtle meanings and a range of emotions within speech, extending its potential beyond just play. This is one reason why laughter is contagious; it invites others to share in our emotional state. Just hearing laughter clips can trigger smiles or laughter in ourselves by activating key regions in our brains. Interestingly, participants in a study laughed significantly longer and more frequently when watching a funny video in the presence of another person, even if they reported feeling the same level of amusement. Human laughter is also generally louder than the play vocalizations of most animals, possibly because our laughter not only serves as a signal between individuals but also acts as a broadcast to those around us. Studies have shown that observers from around the world, and even infants as young as 5 months old, can distinguish between close friends and acquaintances based on brief clips of their laughter. Similarly, we can discern genuine laughter from fake based solely on the sound. Fake laughter is produced using networks in the brain related to speech, while genuine laughter stems from older networks shared with other animals for their vocalizations. Laughter is not only socially important, but it is also believed to be beneficial for our well-being. When we laugh, our brains release neurotransmitters like endorphins, which make us feel good, and reduce stress hormones like cortisol. Some research even suggests that individuals who laugh more can handle stress better and enjoy better cardiovascular health. Laughter is a universal behavior among humans, and babies can even laugh before they can speak. While it may not cure all ailments, laughter undoubtedly improves our quality of life, strengthens relationships, and potentially enhances our health. So, it’s always a good idea to have a laugh, unless, of course, you have a broken rib or something. In that case, it’s definitely not a laughing matter.