Do you think boys prefer girls of their age or a little younger and why?

I know it varies in different age groups so let's say 17 to almost 20 because that's teen to a technical adult. What are the downs and up of the situation from both perspectives or which ever you think you may know. Sometimes I think the younger person might be more interested in an older person because of how immature those in their age group are with mind games and that they just want to get laid. Or maybe a mixture of that and a bad relationship that pushes you away from the interest of dating in school like if the relationship had really been emotionally abusive or rumors. I think it makes you want to just stay away from going for a boy who you think is quite familiar with his strategy or tactics and intentions.