Kate McAllister asked:
Do other animals laugh?
We put this question to Professor Sophie Scott from University College London....
Sophie - Well, they seem to. Wherever you find laughter, it has very similar properties. You find it associated with tickling and you find it associated with play. In fact, there was a really nice work done with rats working on ratís vocalisations and get the sounds that they made when they were distressed.
To do this, what you have to do is record the rats and transducer the sound down in a pitch that we can hear it because rats are so much smaller than us and they make their high pitch sounds. We can't hear them. So, they noticed, once they've done this, that the rats made other sounds. For example, when the rats were playing with each other and rats are very social animals. When they play with each other, they made a different sound and they want to know if that was something like laughter, so they started tickling them and they noticed that the rats made the same sound when they're tickled.
In fact, if the rat tickled and tickled the same rat every day, the rat will start making that sound when they see you. It just that sort of, you know, you've got that kind of Ė if you've ever been with children, you're sort of playing with children, you get that sort of tickling thing and they'll start laughing even if they think you're going to do it. Itís going to get that sort of quality to it. Itís like the relationship with play. Your relationship with play is very interesting because wherever you find play, you find laughter. And play is another very basic mammal behaviour. You find it across all mammals. Itís a sign. If you just watch a group of children playing, itís a sign that they are playing, that they'll make these laughter sounds to indicate this is all a game. So, I think there's probably a lot more laughter out there amongst other mammals certainly, maybe other animals as well. And weíll just go ahead looking for it.
Hannah - Can you demonstrate what kind of noise the rat or the mouse laughter is if you convert it with something that a human ear can hear?
Sophie - It sounds to us like a sort of chirrupy chirp.
Sophie - It doesnít sound like laughter whereas you heard a chimpanzee laugh, you would think that sounds like laughter so it sounds like this. Itís unrecognisably like laughter.
Hannah - As in aside, do you think that laughter is something that babies learn as a child and they know that they're getting a very good reaction from adults? So, is it innate or is it a learned skill?
Sophie - I think itís probably something that will emerge whether or not those babies have experience of seeing if you're hearing it. So, there's evidence that deaf and blind babies smile and laugh, whether or not they've seen or heard somebody else doing that. What you can do is however, you can prime that and sort of encourage it.
So, we know from the rats that the rats who laugh more when they're tickled as adults are the ones who were tickled abundantly in infancy. So, itís prepotent response. Itís something weíll do, a behaviour we will produce whether or not we see an example of it.
But you can encourage it and one of the things that I'm very interested in is, why an adult with people who have very different experience with laughter. So, every time I talk about laughter online or in some public event or meet somebody who says, ďI find things funny, but I never laugh.Ē Iíd really like to know why some people laugh at the drop of their hat while other people are much less likely to exhibit the behaviour although it doesnít affect their enjoyment of things but is not laughing. So, Iíll be interested in knowing sort of how those developmental experiences feed into adult behavioural stuff around laughter.
Hannah - Thanks, Sophie and weíll be returning to Sophie later in the show to find out exactly what's going on in the brain and body during laughter.