Chris Knight writes:

The central question that anthropologists ask can be stated simply: ‘What does it mean to be human?’ In search of answers, we learn from people around the world – from city-dwellers to those who live by hunting and gathering. Some of us study fossil hominins such as Homo erectus or the Neanderthals; others look at related species, such as apes and monkeys.

Something that sets us apart from these ancestors and primate relatives, and should be of special interest to anthropology, is our unique propensity to laugh. Laughter is a paradox. We all know it’s good for us; we experience it as one of life’s pleasures and a form of emotional release. Yet to be able to laugh, we must somehow cut ourselves off from feelings of love, hate, fear or any other powerful emotion. The fall of a pompous fool slipping on a banana skin is the cliché of comic routines; we laugh at his misfortune because we don’t really care.

A helpful way to get a handle on laughter is to place it in evolutionary context. Other animals play, and their playful antics can prompt vocal sounds. But human laughter remains unique. For one, it is contagious. When a group of us get the giggles, we soon become unmanageable. The evolutionary psychologist Steven Pinker notes that this might be what allowed laughter to be pressed into the service of humour. In How the Mind Works (1997), he writes:

No government has the might to control an entire population … When scattered titters swell into a chorus of hilarity like a nuclear chain reaction, people are acknowledging that they have all noticed the same infirmity in an exalted target. A lone insulter would have risked the reprisals of the target, but a mob of them, unambiguously in cahoots in recognising the target’s foibles, is safe.

Besides contagion, laughter also leaves us peculiarly helpless and vulnerable. We can be doubled up with laughter, or laugh until we weep. Physiologically, it can come close to crying. Nearly every aspect of the body – voice, eyes, skin, heart, breathing, digestion – can be powerfully affected. What we find funny might vary by culture, but people across the world make essentially the same sounds.

When we apply Darwinian theory to laughter, it’s tempting to look for a plausible precursor among our ape-like ancestors. The primatologist Jane Goodall, for example, points out that young chimpanzees often engage in tickling games, making huffing and puffing noises all the while. Maybe, then, human laughter is best viewed as an evolutionary extension of certain playful vocalisations already found among apes.

The objection to this theory is that ape tickle-play vocalisations don’t sound like human laughter at all – they are more like heavy breathing, with inhalations and exhalations equally audible. Another problem is that the apes’ sounds are not socially contagious, and don’t bond the group together in quite the same way. No chimpanzee will laugh just because others are doing so – each animal must itself be tickled.

By contrast, when humans meet up on social occasions, the most frequent sounds you’re likely to hear are not grunts and screams but ripples of laughter. Those sounds convey a certain level of relaxed happiness in the company of others. Although monkeys and apes can be friendly, their face-to-face social dynamics are typically competitive and despotic in ways that humans tend to find intolerable. Everyday encounters between nonhuman great apes oscillate between dominance and submission, with facial expressions and instinctive vocalisations to match. There is nothing egalitarian about their encounters. [Continue reading…]