This study not only selected for people who go out of their way to join a society based on high IQ, it also selected for people who open & complete email surveys.
Yes, many practical sampling methods are biased, but it is not difficult for me to imagine that any result here is caused entirely by these biases.
i agree with your criticism in general -- actually it applies to virtually all psychological and medical studies.
but if you think the physical disabilities are better explained by something else to do with this population sample than their iq, you could very clearly publish this theory
Yes, many practical sampling methods are biased, but it is not difficult for me to imagine that any result here is caused entirely by these biases.