As far as I know we only know of three current races where the young mature at a much faster rate than Human children, Klingons, Ktarians and Ocampa. Now for the Klingons and Ktarians we only have Alexander and Naomi to go on as they are hybrids but at least with the Ocampa we know that as well as faster maturity rate they only live for 9 years and I think it's safe to say that they do have a higher capacity for learning. But what about the races out there, like the Klingons and Ktarians, do all there young have a higher capacity for learning (am I using the right term here?) to be able to mature at a faster rate than Humans so that, say, a Klingon 2 year is at the maturity level of a Human 8 year old. Also, skipping into reality now, is it physically possible to have a humanoid species that has a mental capacity to learn faster and mature at a faster rate but then to ease off upon reaching adulthood?