IMO, there is a difference between having a knack with younger girls, and being attracted to them. Another man might have a knack with rich, elderly widows. It seems to me that Wickham was actually attracted to *Elizabeth* at the time (if only in a selfish, superficial way), not Lydia. Don't forget that he also went after Mary King, who as far as we know was of a reasonable age to marry! Of course, the younger the girl, the more naive and easier to manipulate she would be, as well! I don't believe that JA meant to delve into the murky world of sexual predators, especially of young people. To me, the point is that an "ordinary" guy can cause quite enough harm without having any obvious psychological disorder.