Selection Effects

2024-11-21 by Luca Dellanna

#statistics

There's a common belief that attractive people aren't funny, and funny people aren't attractive. But this apparent pattern might be more illusion than reality.

That’s because, even if there were no real connection between looks and humor, we'd still notice many cases where highly attractive people seem less funny than average. It's simple mathematics at work, and the following example explains why.

Let’s imagine that there is no relationship between attractiveness and funniness. If we take a random group of 100 people, both attractiveness and sense of humor will vary, as displayed in the chart below.

Distribution of attractiveness and funniness

If you take the people who score a “10” on the attractiveness scale, their average funniness is going to be 5.5. This means that very beautiful people will be less funny than attractive – even though, and this is key, there is no relationship between the two variables, and it’s all a selection effect!

Selecting the 10s