BBC Column: What makes us laugh?

This is my BBC Future column from a couple of weeks ago. You can find the original here


A simple question with a surprisingly complex answer – understanding laughter means understanding fundamental issues of human nature.

Why do we laugh? Well it’s funny you should ask, but this question was suggested by reader Andrew Martin, and it is a very interesting one to investigate. For what at first seems like a simple question turns out to require a surprisingly complex answer – one that takes us on a journey into the very heart of trying to understand human nature.

Most people would guess that we laugh because something is funny. But if you watch when people actually laugh, you’ll find this isn’t the case. Laughter expert Robert Provine spent hours recording real conversations at shopping malls, classrooms, offices and cocktail parties, and he found that most laughter did not follow what looked like jokes. People laughed at the end of normal sentences, in response to unfunny comments or questions such as “Look, it’s Andre,” or “Are you sure?”. Even attempts at humour that provoked laughter didn’t sound that funny. Provine reports that the lines that got the biggest laughs were ones such as “You don’t have to drink, just buy us drinks,” and “Do you date within your species?”. I guess you had to be there.

Brain triggers
So if we want to understand laughter, perhaps we need to go deeper, and look at what is going on in the brain. The areas that control laughing lie deep in the subcortex, and in terms of evolutionary development these parts of the brain are ancient, responsible for primal behaviours such as breathing and controlling basic reflexes. This means laughter control mechanisms are located a long way away from brain regions that developed later and control higher functions such as language or even memory.

Perhaps this explains why it is so hard to suppress a laugh, even if we know it is inappropriate. Once a laugh is kindled deep within our brains these ‘higher function’ brain regions have trouble intervening. And the reverse is true, of course, it is difficult to laugh on demand. If you consciously make yourself laugh it will not sound like the real thing – at least initially.


There is another fundamental aspect to laughing. All humans laugh, and laughter always involves a similar pattern of whooping noises. Deaf people who have never heard a sound still make laughing noises. The laughing noises produced by humans share many of the acoustic properties of speech, further evidence laughter is hijacking the brain and body apparatus that we use for breathing and talking.

But this does not fully answer the original question. Even if we identified the precise brain areas associated with laughing, even if we were able to make someone laugh by stimulating part of their brain (which can be done), we still don’t know what makes people laugh. Yes, we know about the effect, but what about the cause, that is, the reason why we laugh in the first place?

Shared joke
To answer this, perhaps we need to look outwards, to look at the social factors at play when people laugh. I’ve already mentioned Provine’s study of laughter in its natural context. Provine showed that laughter is used to punctuate speech, it doesn’t just interrupt at random. This suggests that it plays a communicative role – it isn’t just some independent process that happens to us while we are talking to someone. He also found that the speaker typically laughs more than the audience, and that laughter was most common in situations of emotional warmth and so-called ‘in-groupness’. Again, all strongly suggesting that laughter has an important social role. And it is not always used for positive reasons. For all the good feeling that goes with laughing with someone, there is also a dark side, when someone is laughed at to belittle or show disdain.

Perhaps the most important social feature of laughter is how contagious it is. Just listening to someone laugh is funny. To test this, try keeping a straight face while watching this video of a man tickling a gorilla. You can even catch laughter from yourself. Start with a forced laugh and if you keep it up you will soon find yourself laughing for real.

What these observations show is that laughter is both fundamentally social, and rooted deep within our brains, part and parcel of ancient brain structures. We laugh because we feel like it, because our brains make us, and because we want to fit in socially. All these things are true. But biologists distinguish at least four fundamental types of answer you can give to explain behaviour: “why did it evolve?”; “how did it evolve?”; “How does it develop across the lifespan?” and  “how does it work?”.

This column has given some answers to the first question (laughter evolved for social interaction) and the last question (laughter is controlled by evolutionary ancient brain centres that control breathing and speech), but even with the beginnings of answers to these two questions, the other two are far from being answered. Each time we get closer to an answer for a fundamental question, it deepens our appreciation of the challenge remaining to answer the others.

Thank you to Andrew Martin for suggesting the topic. If you have your own suggestions please send them to

Berlin plan #3: Instant social knowledge through unconscious perception

So I think I’ve figured out the third and final intervention I want to run for the cognitive science safari I’ll be leading in Berlin on the 11th of July. Regular readers will recall that I first wanted to try a field test of the change blindness phenomenon, and to follow that up with an exercise in contaigous attention. For my final trick, I’m going to try something which demonstrates how rapidly, and successfully, we can make unconscious judgements about people.

There’s a powerful demonstration of this that I experienced thanks to Professor Jon May during my undergraduate degree. Jon showed the class black and white photos of middle aged men and women and asked us to judge if they were American or British. There were no obviously clues, no cowboy hats, no uniforms or flags. Just boring pictures. If you had of asked any of us in the class we would all have said that we had no idea who was American and who was British. It just wasn’t possible to be sure, but we all guessed and – of course – at the end of the demonstration we found out that we’d mostly been right. It’s an important demonstration that we often have access to information that we aren’t fully aware of or certain about. We couldn’t make judgements on explicit criteria, but instead relied on a perceptual intuition. Without realising it, we’d been trained by experience to associate certain things – styles of haircut? certain facial features? clothing? who knows – with the different nationalities.

So it seems that throughout our lives we’re building up tacit knowledge of how we expect different kinds of people to look. This effect isn’t just for nationalities. Famously, it also seems to work for things like sexual orientation. This is a remarkable paper :Brief exposures: Male sexual orientation is accurately perceived at 50 ms. As the title suggests, it shows that people were able to judge at above chance rates if someone was straight or gay merely from a photo of their face shown for a twentieth of a second. It’s not quite instant, but it shows that even the briefest of flashes can contain a surprising amount of information. You can try a version of this experiment yourself, thanks to the wonders of the internet, with the “Gay? or Eurotrash?” game (via this neurocritic post).

What I’d like to try in Berlin is a demonstration of this phenomenon, but for geography. Using the group of people on the tour, I will find willing volunteers from around Berlin and ask them where they come from. Then we’ll ask the tour to try and guess, through a series of Yes/No answers like “Is this person a European?”, “From Germany?”, “From Berlin?” and so on. Through what has been called the wisdom of crowds we should be able to take the average guess of those on the tour to come up with a more accurate judgement than any one of us will individually produce. The fun will be in seeing how often we are able to judge someone’s hometown from no more than how they look.

A Bigger Apple

The Open University’s blog has a fascinating piece on why New York City has seen an astonishing drop in crime, against the predictions of most social theories.

Twenty years ago most criminologists and sociologists would have doubted that a metropolis could reduce this kind of crime by so much. Although the scale of New York Citys success is now well known and documented, most people may not realize that the city’s experience showed many of modern America’s dominant assumptions concerning crime to be flat wrong, including that lowering crime requires first tackling poverty, unemployment and drug use and that it requires throwing many people in jail or moving minorities out of city centers.

Instead New York made giant strides toward solving its crime problem without major changes in its racial and ethnic profile; it did so without lowering poverty and unemployment more than other cities; and it did so without either winning its war on drugs or participating in the mass incarceration that has taken place throughout the rest of the nation.


Link to ‘How New York Beat Crime’ (via @mrianleslie)

Dramatically titled neuroscience story

Question about your life. Introduction to a thematically related tragedy. Promise of hope.

Over-simplified premise. Mention of a brain part and an inadequately explained technology in the same sentence.

Dramatic claim of a breakthrough.

Researcher and affiliation. Description of motivation related to a minor personal detail.

Overly-technical account of experiment.

Contrived analogy.

Rhetorical question?

Allusion to a controversy.

Quote from the researcher. Quote from another researcher.

Caution about over-interpretation. Over-interpretation. Mention of future work.

Genuinely insightful point.

Unintentional irony.

Earnest but misleading conclusion. Optimistic ending.

With apologies to an old kuro5hin post.

A geography of stigma

The picture below is of the main building to Princess Park Manor, a luxury housing development in North London, that used to be Colney Hatch Lunatic Asylum.

A recent newspaper article about the apartments notes how they have become an attraction for pop singers and reality TV stars.

The Princess Park Manor website lauds the historic buildings but has a history section that completely avoids the fact that the building was an asylum – Europe’s biggest no less.

But this attempt to distance the local area from associations with mental illness is not a new phenomenon. In fact, this area of London has been uniquely affected by trying to dissociate itself from the hospital.

The asylum was so named because it was located in a historic area called Colney Hatch.

As the hospital became infamous in London (it housed almost 3,500 patients at one stage so became well-known), the Colney Hatch name became irreversibly associated with madness. Being called a ‘Colney Hatch case’ was a standard insult.

As a result, simply being associated with the area was stigmatising and house prices began to be affected.

The solution was to rename the whole area to New Southgate. The train station was similarly renamed – originally called ‘Colney Hatch and Southgate’ and then ‘Southgate and Colney Hatch’ but finally the mention of the feared name was omitted entirely, settling with just ‘New Southgate’.

Eventually, the hospital itself was renamed to ‘Friern Hospital’

In fact, the only reference to Colney Hatch that remains in the area is the road Colney Hatch Lane which can also be called the B550 if you prefer.

Curiously though, the hospital had its own cemetery on site although I could find no trace of it on my explorations. Presumably it has been built over as the rest of the estate was sold off.

Link to piece on the history of the area.

Gene environment interaction of your neighbourhood

The amount genes and the environment contribute to our behaviour varies across the country and a new study has mapped exactly where the differences lie.

As well as an interesting finding in itself, the study also highlights an important but often misunderstood point about heritability.

The map on the right is from the study, and generated by the freely available software the research team have created. It shows the results of a large twin study that has been carried out with the help of families across the country.

Twin studies allow us to work out the amount of influence the environment and genetics has on particular trait by comparing the outcomes in identical twins, who are as close as you’ll get to being genetically identical, and non-identical twins, who share only 50% of their genes.

The map shows how much genetic contribution there is to the difference in ADHD symptoms across the UK. You’ll note that genetics makes much more of a contribution to the difference in ADHD symptoms in London than in other parts of the country.

In other words, it’s daft to give a definitive answer about ‘how genetic’ ADHD is, because the expression of genetic tendencies depends on the environment.

That’s not to say that ADHD or any other mental disorder are completely flexible with regard to their environmental and genetics bases, as there are limits and these are likely to be specific to the problem.

But it is also the case that with complex outcomes like mental illness it’s impossible to say that a particular one is solely a ‘genetic disorder’.

There’s a good write-up of the study on the King’s College London website and both the scientific paper and the software are freely available.

The software lets you map the genetic and environmental contributions to a wide number of outcomes that were measured by the study – everything from height to school performance to ADHD.

Link to write-up of study.

Behavioural profiling in casinos

Online culture magazine limn has an amazing article on the use of high-tech behavioural profiling in casinos that lets the house target its gaming to where it cashes in most.

Due to the fact that most games are now networked and most punters have been persuaded to play by a swipe card that can be tied to their personal details every last action can be recorded and analysed.

There is now dedicated behavioural analysis software that allows casinos owners to see how they can best target specific demographics.

The casino’s data cloud, when animated and queried, had rendered visible the fleeting, real-time contours of a behavioral group whose constituents, seated at individual play terminals and immersed in the solitary activity of play, were likely unaware of their kinship. Casino managers attempted to profit from the proclivities of this touch-point collective by carving out a physical space for its members and formally inviting them to gather there—not to socialize, but to continue to interact with their own game screens. Although the players were affiliated by age, gender, game preference, and ultimately a common gathering site, the collective they formed was “virtual” in the sense that it took shape and subsequently became meaningful through casino data analysis and visualization software rather than through self-selection, voluntary participation, or shared experience.

The article is a little jargon heavy but it gives an candid insight into how you appear to the data-hungry casino.

By the way, the whole issue of limn is on ‘Crowds and Clouds’ so there’s plenty of other great stuff for people interested in social psychology.

Link to article on ‘Crowd Contouring’ (via @somatosphere)
Link to latest issue of limn on ‘Crowds and Clouds’