3rd year dental student here, currently in orthodontics right now.

There's two classifications going on here that I think you're mixing up. Skeletal and Dental. I think what you're referring to is a dental over its, known as Class II occlusion, of which there is two variants.

The development of the class of bite you have, whether Class I, II, or III (Normal occlusion, Overbite, and Underbite respectively) is based on multitude of factors. Genetics being a large part of them, but this is definitely a case of "nature vs nurture." Only about 5% of the cases have a known etiology, the rest are in the air. You may even be born genetically with a class II occlusion but because of the way you eat or breath or use your lips or whatnot, may develop into another class. Tooth size is also factor, arch size another, and really another big one is the process of eruption and disturbances during that time which at which they may result in permanent teeth erupting earlier than they should (due to premature loss of primary/baby teeth) and so fourth.

This is a very complicated topic and one where not much is known. Most malocclusion becomes compensated by the body in one shape or another, but that usually doesn't put the teeth in a way that is healthy for their longevity and especially the effect it has on one's ability to maintain personal oral hygiene.