What skills are purely inherent?

I’m talking about skills that you have to be “born with”, or an additional level of skill - skills that some people can have, that no amount of training or practice will bring anyone else up to the same level as. Do you believe there are such skills/abilities ( or levels of skills/abilities)?

On top of this, what people would you consider to have these inherent skills? Do you believe Mozart, for example, had a level of musical ability that is unreachable by any normal person through practice? Could, after decades of study and work, someone reach that level of performance? Or do you think that maybe to say such things of him are overrated - that his musical ability is not outside of any average person’s grasp?

On the other hand, do you think there are people who are entirely incapable of learning a skill to a “normal” level? That, no matter how much time they spend trying to build their abilities, they will never be able to reach the level of skill normal people have?

Everything to some degree. You neglect the fact that there ARE thousands of people in every conceivable activity that spend decades trying to be the best at what they do. It could be chess or marathon running or one of countless other pursuits. You are born with a certain set of atributes and while you can almost always improve with practice and dedication, you will hit a wall at some point and that point will probably be lower than some others.

Good nutrition helps one develop their maximum height but someone probably aren’t isn’t to be a great basketball player if you top out at 5’4". Any conceivable test of mental aptitude shows that individuals are constricted to a rather narrow range of raw mental abilities and it because fairly fixed rather early in life (see all IQ tests, school acheivement tests, SAT, ACT, GRE…all of them).

Almost all abilities fall on a bell curve. You have to combine that with effort but extreme ability + extreme effort will define the absolute best.

I would say that most abilities have both a learned component and a component of inherent talent. Your talent gives you the starting level, whether you improve from there depends on how much work you put into it. To a large extent hard work can compensate for lack of talent but someone with an incredible talent, like your Mozart example, and who is willing to put in the work is just going to be better than someone without the inherent gift.

That said there are a few things like perfect pitch that seem to be cases of either you have it or you don’t.

In addition, there are some skills that, if you are going to learn them really well, you have to begin in childhood.

None, really; if it’s a skill then it’s not inherent. Not to play a semantic game but the word you’re looking for is probably attribute or talent. The word “skill” is associated with knowledge and acquired abilities, not ones you’re born with. Besides which, any inborn trait has to have the right opportunity, the right environment, and lots of practice to come to anything at all.

To use your example of Mozart, his level of ability was partly inborn and partly fostered. His father was both a musician and music teacher and pushed little Amadeus to succeed from a very early age. While his precociousness indicates a high level of innate ability, Mozart was a product of intense training and practice. If he’d been born to a well-digger instead of a music teacher, he probably never would have become famous for anything at all since his talent for music never would have been developed (and excellence in digging holes has never been lauded).