>>11123781This is true of all animals. Indication of intelligence based on the ratio of brain mass to body mass. Homo sapiens one of the top. Both European and Asian homonids that mixed with homo sapiens had larger brains.
One speculation on the subject of autism looks at the idea that higher neuron development from neander admixture descendants may cause higher neuron density in the smaller homo sapiens skull leading to the neurological problems faced by those with autism
