I personally do not believe that there is a gene which predisposes one to becoming a ped; I remember quite distinctly how and when it happened to me, at the age of 45, no less.

For starters, to a true ped, the attraction is more emotional than physical.

Next, I would offend (and already have offended) the more politically correct among us if I gave an opinion on the rise of pedophilia which seems to correspond with the rise of the Women's movement. Coincidence, maybe, but more than once it has been brought to my attention by other peds that they are simply turned off when females surrender their femininity to become "persons" (before the flames begin, let me remind you that it was not the case with me, since I was totally and unequivocally attracted to women before my epiphany).
I will concede this much, however; since being shown the light I have almost no patience with the manipulative and deceptive games that all too many women play, nor am I unique is this respect. This is not politically correct either (good!).

Another theory that I have never seen advanced anywhere is the common yearning to return to the halcyon days of childhood, which always seem better in retrospect.

Yet another theory is that, in an overcrowded world, a female who can offer the joys of intimacy and not add to the population explosion is intrinsically desirable.

Nor should one overlook the rewards of mentoring someone.

And let us not forget the satisfaction of showing someone the hypocrisy of a society which condemns Love in almost any form that does not boost the economy is some way, while strengthening them with the ability to see through such hypocrisy before they join the ranks of the befogged and benighted.

We should also remember the the sheer joy of loving someone who brings neither emotional baggage nor cynicism to the relationship.

And what about the attraction of being involved with someone who sees the world through fresh eyes, and can bring this spontaneity to the relationship?

Much of this is the same attraction that parents feel for their children, which may have much to do with the prevalence of incest in many cultures.

Personally, I think that there is more to it than simply 1 gene.