陪审员选她当陪审长，理由是「你上过法学院」：可她只是在《律政俏佳人》里演过律师，连大学都没念完

First what happened, then why it is interesting.

The person here is the American actress Reese Witherspoon.

In 2001 she starred in a film called Legally Blonde.

The plot, put simply: a young woman everyone assumes is only good at dressing up gets into Harvard Law School and ends up an excellent lawyer.

The film was a hit at the time, and twenty-odd years on, a lot of people are still watching it.

One thing needs stating first: the actress herself has never studied law.

She puts it very plainly — she did not finish college.

All right, now for the main point.

In America, ordinary citizens are called at random to serve on a jury.

It is an obligation, and famous people are no exception.

The jury's job is different from the judge's.

The judge handles the law; the jury handles the facts — whether a thing actually happened.

Whether damages are owed, and how much, is usually decided by a vote among these dozen or so ordinary people.

Seven years after the film came out, her number came up.

The venue was Beverly Hills, the case a dog-bite civil suit, and it ran two weeks.

On the first day the jury has to elect a foreman from among themselves.

The foreman's job is to run the discussion, keep order, and read out the verdict on behalf of everyone at the end.

The position does not require any knowledge of law — but in practice, whoever is chosen tends to shape where the discussion goes.

They looked round the room and chose her.

She was taken aback, and asked: why me?

The reason they gave was: because you went to law school.

She had to explain: I did not go to law school, I did not even finish college.

The reason did not change the outcome.

In the other jurors' minds, she had been a lawyer in a film, and that was enough.

When she recounted it later on a talk show, she said a few things.

She said: I only played a lawyer in one film, once.

She said: and they really did put me in the foreman's chair.

She said: that was the moment I realised how many people do not actually understand how the law works.

You can take this as a joke, and there is nothing wrong with that — but something less funny is sitting underneath it.

The entire premise of the jury system is to have a group of people with no professional background judge the facts.

That design is sound in itself — judging facts runs on common sense, not on statute.

The problem is not that they do not know the law. It is the method they used to pick a leader.

They did not ask who had run a discussion before, who could put things clearly, who could take in a view they disagreed with.

The basis they used was: I have seen this person do this on a screen.

There is a very simple explanation for it: familiarity gets taken for competence.

See someone do a thing over and over and you come to feel they are good at it.

The advertising business has been running on exactly this for a hundred years.

Only this time, it turned up in a courtroom, and the parties were real.

Think about it:

Is there someone around you where you cannot name a single thing they have actually done, and yet you assume they know their subject?

Where did that impression come from?