Two Wrongs

Validate Your Skill

Validate Your Skill

In a book about children’s behaviour 1 I forget which one, and I actually also cannot find it at the moment, so no citation. Sorry. there is a chapter about children and lying.2 It’s interesting! It frames lying in an unusual light. I would recommend reading the whole book if I could remember which one it was! The authors tell about a researcher that has a set of 2.5 minute video tapes of 7–10 year old children telling a briefly rehearsed story from the child’s own life – except only half of the stories came from the child’s own life, the rest are completely fabricated. By court and customs standards, 2.5 minutes of almost continuous talking is an unusually good amount of data from child testimony.

The test is for a viewer to pick out which children tell lies and which tell the truth from a random sample of these tapes.

There are people who work as child lie detectors, i.e. customs officers dealing with immigration cases. These people are supposedly trained at this, because there can be serious consequences to getting it wrong; an incorrect judgment can ruin a family’s life. Thankfully, these people are also fairly confident in their ability to spot a child lying.

Do you want to guess how well they do on a random sample of videos?


Around 50 %.

It’s such a simple skill to test, and yet it seems like nobody working with it did. Their perception of their skill was completely disconnected from reality. Didn’t they get even a little curious?

If you work with something where it’s fairly easy for you to construct artificial scenarios that allow you to validate your skill, please do. Even if it’s not as serious as this case, the world needs more knowledge and less bullshit.

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