> As far as I know there's no way for evolution to "sprinkled a bit of autism" across a population for an increased chance of population survival - I don't see

> As far as I know there's no way for evolution to "sprinkled a bit of autism" across a population for an increased chance of population survival - I don't see how such a mechanism could exist. Not strictly autism, but sickle cell anemia is a disease caused by carrying two copies of a recessive gene. If you have two copies of the recessive gene, you suffer from a debilitating illness. If you carry one copy of the normal gene and one copy of the disease causing recessive version, you have increased resistance to malaria, which has killed more humans than everything else combined. So evolution definitely does contribute to the prevalence of sickle cell anemia. Almost everyone in the US we suffers from sickle cell anemia is of sun Saharan African descent, where malaria is especially relevant. While autism certainly isn't as simple as sickle cell anemia, there does exist the possibility that genetic components which contribute to autism can also contribute to other, more positive traits with fewer risk factors.