Professor Luke O'Neill

Then you looked at the elder one and younger one.

And in Ireland, for example, the average industrial wage is €52,000 a year.

The eldest will earn about €1,000 more per year than the younger one.

And the Danish scientists had seen this, and they wondered why that was, and they came up with a hypothesis.

Now, if you're a scientist, you have to come up with what are called hypotheses, which means an idea.

And their idea was maybe it's to do with infections.

Now, you might wonder why they would have hypothesized that.

It had been known that the second child is more likely to end up in hospital with a respiratory disease than the older child.

And again, that's statistical, and this is a really robust piece of data.

So if you look at the rate of hospitalization,

from respiratory diseases like flu, RSV, infects infants and younger children, the younger child is more likely to end up in hospital than the older child.

And there are studies showing three times more likely.

Now, that's a big difference.

And the Danish guys knew this and they wondered, was that part of it?

And they dug in a bit more deeply.

Why would the second child

be more likely to end up with a serious infection than the older child.

And of course, if you get a serious infection, it means you're out of school or you're in hospital and you're being treated differently as an infant because you're sick.

And the question then was, would that affect them?

They also are able to, again, a bit of speculation, I suppose, but they know, we know that if you have an infection, you get this thing, inflammation, that I often talk about.