Tommy Cooper’s legendary catchphrase – “Just like that!” – encapsulated his effortless comic timing. But was this comedian’s sense of humour written into his DNA? A study conducted in Cooper’s native Wales, involving over a thousand twins, has cast doubt on any strong genetic link to comic talent. Instead, the evidence suggests that whether someone is funny or not is probably shaped more by their environment and life experiences. Here’s Gil Greengross at Aberystwyth University…
Gil – There’s a lot of research about the genetic basis of many cognitive abilities, such as creativity and intelligence, and basically most psychological traits have at least a partial genetic basis. So my prediction would be that humour as well will have a genetic basis.
Chris – Tell us about the study then, how you designed this in order to try and test that, whether there is a genetic element to it.
Gil – We use a twin paradigm, which means that we compare identical twins to non-identical twins. The method allows us to separate environmental and genetic factors because the assumption is that twins, no matter if they’re identical or not, are raised roughly similar by the parents. So any differences that we find will be due to their genes. Now, if identical twins are more similar on a specific trait like humour than non-identical twins, we can infer from that that the trait has a strong genetic basis.
Chris – Because of course, one of the hardest things in this sort of situation to disentangle is the influence of the environment, isn’t it? Because when you grow up together, you’re in very similar sorts of environments. You’ve got the same parental influences, the same educational influences, that kind of thing. But how do you judge what’s funny? Because some people find some things very funny, and other people, it just leaves them cold. So how did you judge that’s a funny person and that’s not a very funny person in order to then make a valid comparison?
Gil – Humour is to some extent subjective. However, we found in different studies that people tend to agree to a large extent on what’s funny and what’s not. What we did in our study, we gave people cartoons without a caption and asked them to write a funny caption to the cartoon. Then later, we gave these captions with the cartoon to judges that didn’t know anything about the study, that didn’t know the age, that didn’t know that the twin involved, the gender, and so on, and just asked them to rate it from one to five. And each caption was rated by at least five different judges, and they were mostly in agreement with that. And that’s how we knew who were the funnier individual and who were not.
Chris – Was there a genetic slant in this? Do the identical ones show that their ability to be funny is strongly genetic or not?
Gil – So surprisingly not. So this is kind of counter to all the research really in the field. We found that there is no genetic basis for humourability. Now, this is, of course, the first study that actually examined this question. So I’ll be cautious about the conclusion. But what we found is that the sources of individual differences were solely due to environmental factors, both the shared environment, like the parent, and then the non-shared environment, the unique friend that each twin has.
Chris – How did this make you feel then? Because you went into this thinking, we’re going to see a strong genetic effect because the brains are going to be wired in a similar way in these identical twins, and that’s going to make them think along similar lines, and I’m going to see a strong genetic correspondence to the humour that they’re able to express. You didn’t find that. So did that make you laugh?
Gil – Yes, funny in a more disappointing way, in a sense. Yes, at first I was a little disappointed, but then, again, science is unpredictable. So sometimes you don’t get the results that you think they are. Otherwise, it won’t be very interesting. And maybe we found something new. Maybe humour as a trait is very different than intelligence and creativity, because it involves a lot of different aspects, facets. It’s not like a single thing to measure. And also, our task was slightly artificial. Writing captions is not something that people use every day. So maybe we need to look at how people use humour in their daily lives and how they interact with others and how humour erupts spontaneously in conversation. That will be maybe a more adequate way to measure the genetic factors of humour.
Chris – And where next then? Now you’ve killed that hypothesis. What next?
Gil – Well, the next step is actually to try to replicate the study. And we’re currently running a replication study with a different set of twins. One of the problems with our study was that our sample was quite old, about 66 years old, also skewed mostly women. So that might have an effect. So we have a different kind of a cohort group in a different culture in Finland. And we’ll see if we get the same result. If we do, then we’ll have more confidence that indeed humour doesn’t have a genetic basis.