For this explanation would there be core skills that every person in childhood possesses and any specific skill learned would be a branch off of this main skill? For example, motor skill is a core skill and a specific skill learned later in life if dribbling for soccer. In order to be able to dribble you need to first develop your motor skills, meaning dribbling is a more advanced motor skill.

I know that infants tend to feel things with their feet rather than their hands. I wonder if our sensitivity in our feet get worse as we age. Especially because we use shoes nowadays, so we don't need them to have the same capabilities as our hands to interact with the world.