Humour is one of humanity’s most cherished forms of connection. It disarms tension, bridges divides, reveals intelligence, and generates joy in both social settings and in the workplace. But humour didn’t appear out of nowhere. Long before stand-up comedy, internet memes, or dry wit, there was laughter — breathy, involuntary, and born in the bodies of our mammalian ancestors. Understanding humour begins with understanding the evolution of laughter and the deep biological and social roots from which it springs.
🌱 Laughter Before Language: A Mammalian Story
The evolutionary story of humour begins more than 60 million years ago, long before humans walked the Earth. Among early social mammals — from rats and dogs to primates — vocalisations associated with rough-and-tumble play emerged as crucial signals. These weren’t jokes, but rather honest indicators of non-aggression. Laughter-like panting, chirping, or breathy vocalisations accompanied playful bites and chases, telling partners: “This is just fun. You’re safe.”
This early laughter served at least three important purposes:
- ✅ Indicating play intent – to prevent escalation into real aggression.
- 🤝 Bonding through shared joy – helping build long-term social relationships.
- 🧘 Engaging the parasympathetic nervous system – allowing animals to relax and emotionally regulate after arousal.
Even today, rats produce ultrasonic chirps when tickled. Dogs emit “laughs” during play. Chimpanzees pant rhythmically when mock-wrestling. These vocalisations laid the groundwork for the rich, nuanced expression of laughter we now recognise in humans.
🐒 Ape Laughter and the Roots of Emotion
Roughly 10–25 million years ago, the common ancestor of modern great apes developed more elaborate forms of laughter. Among chimpanzees and gorillas, laughter became more complex — used not just during play, but also to strengthen alliances and diffuse tension in hierarchical groups.
This phase marked the beginning of laughter as a social tool, not just a reflex. It also set the stage for a crucial evolutionary leap: the emergence of dual vocal pathways in early hominins.
🚶 Early Hominins and the Social Dimension
Between 2 and 4 million years ago, early human ancestors such as Australopithecus and early members of the Homo genus developed increased control over breath and vocalisation. This allowed for more volitional vocal behaviour — we could now fake laughter, mimic sounds, and eventually produce speech.
This development transformed laughter from a purely affective, automatic response into something that could be strategic, social, and symbolic.
Laughter began to carry layers of meaning:
- 🫢 Spontaneous laughter still signalled authentic emotion.
- 🎭 Polite or strategic laughter helped manage social dynamics.
- 😏 Mocking or ironic laughter allowed expression of status, critique, or shared cynicism.
In this way, laughter evolved into a flexible tool for human social navigation — a kind of emotional Swiss Army knife.
🧠 The Birth of Humour: Homo Sapiens and the Rise of Cognitive Play
Humour, as distinct from laughter, likely evolved with Homo sapiens, emerging in tandem with symbolic thought, language, and social complexity around 200,000 years ago.
Where laughter is found in other animals, humour is uniquely human.
Humour requires:
- 🌀 Violation of expectation – something surprising or incongruent.
- 🛟 Safe context – the brain must recognise there’s no real threat.
- 🤯 Cognitive appraisal – understanding the twist, irony, or absurdity.
- 🤝 Shared mental models – appreciating humour often depends on common knowledge or cultural cues.
In evolutionary terms, humour became a signal of intelligence and shared values. It allowed humans to:
- Test group membership (“If you get the joke, you’re one of us.”)
- Diffuse social tension (“We’re okay now.”)
- Critique or challenge norms and hierarchies in non-threatening ways.
- Attract mates or allies by displaying creativity and mental agility.
As Bryant (2020) describes, laughter became embedded in conversation as a way to synchronise, affiliate, and disambiguate communication. It was no longer just a response — it was a signal.
🤣 Modern-Day Social Complexity
Humour has evolved in incredibly complex ways and serves a range of modern social functions. Three of the most important are:
- Colaughter: Joint laughter signals deep affiliation and can be recognised even by infants at 5 months old.
- Contagion: Laughter is contagious and more efficient than overlapping speech in transmitting social closeness.
- Volitional vs. Spontaneous Laughter: Humans can fake laughter, but listeners across cultures reliably tell the difference.
🔐 Humour as Encrypted Empathy
One compelling modern theory, the encryption model of humour, suggests that humour functions like a secret handshake — a way to test mutual understanding. When someone “gets the joke,” they reveal a shared context, belief, or cultural knowledge. When they don’t, we register a mismatch.
In this way, humour is both inclusive and exclusive: it brings people together, but also subtly distinguishes those who “belong.”
🤝 The Bottom Line: Why Humour Matters
Across its evolutionary arc, laughter and humour have always signalled the same essential idea:
“You’re safe here. You’re one of us.”
From the breathy pant of a chimp to a perfectly timed punchline in a Zoom meeting, humour continues to serve our deepest needs: belonging, bonding, and buffering the stresses of life. This makes it a powerful tool not only after-hours, but at work.
And though the words humour and human have different etymological roots — one from Latin umor (moisture) and the other from homo (man) — we like to imagine that they are intimately linked.
Because to be human is to laugh, and to laugh — truly, insightfully, joyfully — is perhaps the most human thing of all.
Evolutionary Timeline
| Phase | Time Period (Approx.) | Group | Key Developments | Purpose & Function |
|---|---|---|---|---|
| 1. Early Mammals | ~200 million years ago | Early mammals | Emergence of affective vocalisations (e.g., distress calls, play sounds) | Basic vocal emotional communication for survival (e.g., parent-offspring bonding, social cohesion) |
| 2. Social Mammals | ~60–80 million years ago | Placental mammals (e.g., rodents, canids, early primates) | Evolution of social play vocalisations — rough-and-tumble play accompanied by ultrasonic or breathy sounds (e.g., rat chirps, dog “laughs”) | Honest signalling of non-aggression, social bonding through play, emotional synchrony |
| 3. Last Common Ancestor of Great Apes | ~10–25 million years ago | Hominids (including chimpanzees, gorillas, humans) | Panting play vocalisations become more elaborate (e.g., chimpanzee laughter); increasingly used in social play contexts | Ritualised communication of benign intent; reinforced affiliative bonds and reduced conflict in social groups |
| 4. Early Hominins | ~2–4 million years ago | Australopithecines, early Homo species | Increased breath control and dual vocal pathways (emotion-based + volitional vocalization); mimicry of affective sounds begins | Laughter becomes more flexible — used strategically for bonding, defusing tension, or even deception |
| 5. Anatomically Modern Humans | ~200,000 years ago to present | Homo sapiens | Integration with language, emergence of spontaneous and volitional laughter; expansion into humour, irony, sarcasm | Laughter and humour serve complex social roles: alliance formation, covert signalling of shared knowledge, managing group dynamics, etc. |
📚 References
Bryant, G. A. (2020). Evolution, Structure, and Functions of Human Laughter. In K. Floyd & R. Weber (Eds.), The Handbook of Communication Science and Biology (1st ed., pp. 63–77). Routledge. https://doi.org/10.4324/9781351235587-7
Gervais, M., & Wilson, D. S. (2005). The Evolution and Functions of Laughter and Humor: A Synthetic Approach. The Quarterly Review of Biology, 80(4), 395–430. https://doi.org/10.1086/498281
Scott, S. K., Lavan, N., Chen, S., & McGettigan, C. (2014). The social life of laughter. Trends in Cognitive Sciences, 18(12), 618–620. https://doi.org/10.1016/j.tics.2014.09.002