Not long ago the HBD community was shocked to learn about a theory claiming that genetic IQ had dropped by about 15 points since the Victoria era due to a combination of dysgenics and mutation load.  Some HBDers were extremely skeptical that such a large drop in IQ could have possibly occured in such a short span of time.  Well one of the scientists behind that theory is now claiming there’s been a 30 point drop in just the last 200 years.  Professor Bruce Charlton writes:

We currently believe that general intelligence has declined by approximately two standard deviations (which is approximately 30 IQ points) since 1800 – that is, over about 8 generations.

Such a decline is astonishing – at first sight. But its magnitude has been obscured by social and medical changes so that we underestimate intelligence in 1800 and over-estimate intelligence now.

A 30 point genetic drop in IQ would imply that that by the standards of people in 1800, people today are mentally retarded!!!

Such an extreme theory goes against everything I thought I knew about IQ and genetics, but I greatly admire these scientists for daring to challenge the conventional wisdom in such a radical way.  It will be interesting to see if such a paridigm shifting idea can gain acceptance by other experts in the field.