[lurquer]

“…tracking nearly half a million children born in Western Australia between 1980 and 2001. Of those, 1,870 developed schizophrenia, but not one of the 66 children with cortical blindness did.”

Using this data, one would expect to see only 0.25 cases in those 66 blind kids.

Stated differently, there is around a 78% chance of having 0 cases in those 66 by random chance alone.

Dumb.

[solumunus]

“That sample of blind children is small, but the pattern holds across more than 70 years of evidence: not a single congenitally blind person with schizophrenia has ever been reported.”

[debo_]

It's ok, people in the life sciences are very accustomed to people from other fields assuming they are stupid.

[xdavidliu]

this is the type of math they should be teaching in high school, not trigonometry and calculus (which should be electives)

[tim333]

Calculating 1870/500000*66 is kind of basic arithmetic that is covered in high school. They could maybe have some classes in debunking bs media claims which are quite plentiful these days?

[xdavidliu]

I'm of course not talking about the arithmetic, but rather understanding the semantics of ratios, sets, and subsets, and inferring statistical significance.

[commandersaki]

A philosophy course on logic should be sufficient.

[2ndorderthought]

I got all interested and you are right. The math isn't mathing. For social science though this is what they have to do to fund more research. At least there isn't a greater incidence? ... ? ... ?

[yladiz]

Can you explain how you got that number from the quote? I don’t follow.

[bhattid]

Not the original commenter, but the math is (making some implicit, but arguably reasonable assumptions):

Probability that someone in the population has schizophrenia = (1870/500000) = 0.00374

Probability that someone does NOT have schizophrenia = (1 - 0.00374)

Then if we assume that blind people have the same rate of schizophrenia as the population, Probability that 66 blind people ALL don't have schizophrenia = (1 - 0.00374)^66 = 0.78

[lurquer]

The sad thing is that IF — by chance — one of those 66 had schizophrenia, the headline would undoubtedly read “Blind children are FOUR TIMES more likely to develop Schizophrenia!”

[wizzwizz4]

1870/500000*66 = 0.24684. However, it's "nearly half a million", so let's call it 30000 as a conservative estimate: that's still 0.4114 children in expectance, which isn't very many.