47 | August said to be the birth month linked to the highest rates of ADHD

https://www.cnn.com/2018/11/28/health/adhd-diagnosis-august-kindergarten-study/index.html

Notice the number of children in the study.  407k+.  That's a lot like 47.

I assume they're making the point that by being young, and starting school at the time children born in August do, it makes them more susceptible to developing ADHD.  I would say that the illogical ways of the classroom, make everyone more prone to ADHD.