I would tend to agree with you, but all other things being equal (ie, similar values, family background and education, etc.), I think that older guys tend to treat women -- actually, people in general -- better than the younger guys do.
I would think that it has a lot to do with life and experience bringing down the cockyness, arrogance, and narcissism that often come with youth, and young males in particular.
It is often suggested by psychologists that children and adolescents display traits and behaviours that what would be considered symptomatic of psychopathic personality disorder in an adult. But those traits and behaviours usually adjust themselves through socialization. A 20 something man is still being socialized, whereas socialization has hopefully already done most of its work on a 40+ something man.