Dr. Kieran O'Keefe

And my children, if they're watching this, will be horrified at me saying that.

But...

You know, look at the Cottingley Fairies.

Here was a case over a century ago where two young girls, they even had photographs of fairies at the bottom of their garden.

It was a huge sensation and it was investigated by Sir Arthur Conan Doyle, the author of Sherlock Holmes.

He was an individual that was also interested in the paranormal.

He investigated seances and he ended up investigating the Cottingley Fairies and believed without a shadow of a doubt in everything that these two girls were saying.

reputation on it didn't he he came out publicly in the newspapers and said you know these girls are telling the truth these fairies are real absolutely and if we look back at the fairies now we look back at those photographs

you just look at them and they're almost laughable.

It's quite obvious that they're fake.

But he was drawn in by these two young girls and effectively believed everything they said.

So we've got to treat their testimony with a little bit of care.

They don't see it, but then again, is that, you know, a perfect support for a sceptical argument that it is their imagination?

I think it's partly because of my research into imaginary friends.

You know, typically...

you would be dealing with a scenario where you would have repeatable occurrences.

You'd have a number of interactions, sometimes even daily, but definitely on a weekly basis.

But it's a single incident.

That is not something that lends itself to the idea that it's imaginary friends.

But also, the majority of cases, an imaginary friend is human, either a child or a teenager or an adult.