Is the human body's physical developement purposely slowed to match the maturity process of the brain?

Question

why does the human body mature at a slow pace instead of quickly like say a horse? is it because the brain takes so long to mature properly that if a person were the size of an adult human at age 3 say, it could overpower an older person that might be necessary to teach it the knowledge it needs for life?

Answer 1

the brain and body dont necessarily mature in that order some people go thought puberty later than others (It depends on genetics). For instance anorexia can slow the affects of puberty in women. Secondly horses spend more time in the womb than humans do so they kind of have a head start on maturity.

Answer 2

Sounds good, but how does that explain teenagers!