Why do babies laugh?

• Dr Caspar Addyman running the ‘BabyLab’ studying why babies laugh
• Groundbreaking study will survey thousands of families worldwide
• Early research shows boys laugh more than girls in early months

Whether it’s playing peek-a-boo, tickling their tummy or blowing raspberries, parents usually have a failsafe formula for making their baby chuckle.

What most of us probably haven’t done is stopped to think about why babies laugh at these things.

Step forward Dr Caspar Addyman, a Research Fellow at London Birkbeck University’s Centre for Brain and Cognitive Development — or the BabyLab as it has been dubbed. He is overseeing one of the biggest studies into what makes babies laugh, and why.

‘Understanding babies also helps us understand adults,’ he says. ‘Babies are little scientists. They are discovering the world and through them we can discover a great deal, too.’

So passionate is he that Dr Addyman — a banker turned psychologist who doesn’t have any children — is funding the research himself.

He’s created a detailed questionnaire for parents, as well as asking them to send in videos and short reports of what makes their babies laugh.

So far, 1,400 parents from 25 countries have answered questions ranging from whether their baby was more likely to laugh at a particular time of day to which toys and nursery rhymes they found funniest.

‘We also asked whether they found Mummy or Daddy funniest and what the baby’s general temperament was. We are also working on a separate questionnaire to work out whether there is a correlation between laughing babies and a calmer temperament,’ Dr Addyman told the Mail.

‘The big surprise has been that, contrary to general perception, laughter is present from a very early age,’ he says.

‘Ninety per cent of babies have smiled in the first two months and laughed just a few weeks after that, while we have had reports from parents that their baby has laughed unambiguously at just a few weeks old.

Happily, mums and dads appear to score equally when it comes to making a baby chortle.

However, it’s the boys who seem to have the biggest sense of humour, with parents reporting their sons laughed nearly 50 times a day in contrast to a mere 37 for daughters.

‘This could be reinforced by the behaviour of parents,’ says Dr Addyman. ‘If you think your boy baby is laughing more, you may try to make them laugh more.’

‘Laughter is foremost a social thing. You laugh in company,’ he says. ‘One of the clearest bits of evidence we’ve found is that it is not necessarily what you are doing, but the fact you are present with your baby that’s important — that is why they are happy.

Moreover, in the first year, smiles and tears are a baby’s only way of communicating. ‘Crying is a signal they want something to change, while smiling or laughter is the opposite — it says keep doing what you’re doing.’

What’s tickling Mr Tickle?

The parents of three-week-old Cosmo sent the BabyLab a series of pictures clearly showing him laughing as they tickled him, challenging the idea that babies don’t laugh until they are older.

‘The first way to get babies to laugh is through touch,’ says Dr Addyman.

‘Tickling has deep evolutionary roots that come from being a mammal. It’s partly related to grooming, a vital function that is also pleasurable.’

And as grown-ups know, tickling stimulates different nerve endings, which we normally react to with laughter.

Who’s looking at you?

And then there are babies who always laugh when they see themselves in a mirror — though, as Dr Addyman explains, it’s not for the reason that parents tend to think.

‘Research suggests that babies don’t recognise themselves in the mirror until they are at least 18 months old,’ he says.

What’s so funny, then?

Dr Addyman believes that the mirroring of expressions breaks natural social conventions, and babies find this funny.

‘Conversation and social interaction involve turn-taking, but the person in the mirror is breaking these conventions by doing everything at the same time.’

Splish splash!

‘A lot of parents report that their babies find bathtime funny, which I think is linked to the supervising adult’s undivided attention,’ Dr Addyman says.

‘But it’s also down to sensory pleasure. Water is warm and womb-like. They also get pleasure from simple, elemental feelings and sensations.

‘One of the nicest reports was from a mum who told us her baby laughs wholeheartedly when she stands under the shower after she’s lifted out of the swimming pool.

‘She described it as a laugh of sheer joy at being in the world and I think there is an element of that about being in the bath.’

Peek-a-boo… I see you!

No parent will be surprised to hear that peek-a-boo tops the worldwide list of laughter-making games.

Dr Addyman believes it works because it is intensely interactive and also a game that can develop over time.

‘A young baby has no concept of time, so each time someone or something returns that has disappeared it is a shock.

‘And because peek-a-boo has their much-loved parents “coming back”, it’s a happy shock for the baby.

‘Over time the game becomes more sophisticated because babies develop a sense that you will come back — so it becomes about anticipation, the fun that is still to come heightens their amusement.

‘When they grow into toddlers, they realise they can make you disappear and reappear if they cover their own eyes, as with this little girl. So, in microcosm, peek-a-boo shows how a child develops.’.

Puppet on a string

Parents overwhelmingly reported that dolls and puppets were their baby’s funniest toys.

‘Early on, babies seem to understand at some deep level that their toys are not real beings, but are still able to have a degree of empathy with them,’ says Dr Addyman.

‘And they also seem to find the incongruity of an animal or inanimate toy behaving in a human fashion very amusing.

‘As with peek-a-boo, it’s because their parent is there as part of the game, too, orchestrating the interaction.’

Rattled by fun

Some parents reported their babies are endlessly delighted by the rattle, when they shakes it and when the parent shake it for them.
‘Sometimes a baby’s laughter is triumphant — a form of “I have made this happen,’’ ’ says Dr Addyman.

‘And sometimes it can just be because there is a pleasing noise or sensation that is new to them. I think there can be a cause-and-effect connection, too.

‘One of the videos we’ve been sent is of a baby laughing when their parent presses a light switch and the light comes on and goes off. It’s hilarious every time, and it is the same thing with a noisy rattle’, he adds.