Who checked this?

A father in Jeddah receives a message in the family group. A new study, it says, shows that a particular powder stirred into milk each morning makes children taller and sharper at school. There is a chart. There is a phrase about researchers. It has been forwarded many times.

Not long ago, a claim that looked like this had usually been through something before it reached him. Someone had to pay to print it, a publisher or an editor had to agree, and a journal had to accept the paper before anyone could call it a study. The filters were slow and sometimes wrong, but they removed a great deal of nonsense on the way.

Most of those filters have gone, and in many places that is a good thing. Anyone can write, film, record and sell now, and plenty of voices are being heard that never would have been.

But a study is not a song. When the aim is to be shared quickly, there is little reason to do the slow, expensive work of finding out whether something is true. A small sample, a convenient chart and a confident headline cost almost nothing to produce, and almost nobody reads past the headline.

So the work of checking moves to the reader. Did the people behind it show how they did it? Has anyone qualified, with no stake in the outcome, looked at it and agreed? Who benefits if the father believes it, and are they the same people telling him?

Notice where nobody needs to ask. A builder who claims a cheaper cement is just as strong is found out by the first wall that cracks, so few people bother making the claim.

A claim about a child's height never meets its wall. That is exactly where it is worth someone standing at the gate again, and often that someone is us.