How long a man is able to last is not the important factor in diagnosing premature ejaculation. The crucial issue is if a man is satisfied with the length of coitus. Premature ejaculation often occurs during the first experiences with sex, and in this case is most commonly attributed to anxiety. The majority of men gradually learn to control their orgasm, and have no lasting effect. Some men will develop a longer-term anxiety toward sex, which can cause a prolonged experience with premature ejaculation.
Sexual behavior is also a factor.
The longer the period since last ejaculating, the quicker young men typically reach orgasm. Younger men tend to ejaculate more quickly than older men, as experience seems to be associated with ejaculatory control.