This may not please anyone, but the fact that a man is sexually attracted to a 12 year old boy or girl doesn't mean he would act on it. It's the out-of-control sexual predator that society is concerned with--not those members of society that have attraction only.
We all have strong attractions that we don't act on. Think of all the times you have 'lusted' after some celebrity or actor/ress. I mean seriously coveted him or her. Then think about the number of fans with such crushes that stalk and are a danger to the actor or actress. It's the 2% who act criminally on attractions that we should be concerned with.
I'm not trying to defend men or women who are attracted to children. I was molested as a child, and I know personally the impact of such a thing on the entire life of the child. What I am saying, is you can't judge the real problem to society by looking at attractions alone.
I don't think you can even begin to look at a DNA connection by looking at attractions alone. You can use an MRI to see what stimulates parts of the brain, but you don't get any help in discovering what might or might not lead to acting criminally. You get no data on impulse control.
What makes one teenage boy restrain himself when a teenage girl or boy says "no", even though his hormones are raging? What makes another teenage boy act on impulse only and rape a girl or boy? It's not about attractions alone. Both the boy with restraint and the boy who rapes have similar attractions at play. Similar raging hormones. The difference is in impulse control. I would think that would be a more informative study.
I read an interesting article to day on psychopaths..
Lack of empathy, guilt, conscience or remorse
Shallow experiences of feelings or emotions
Impulsivity and a weak ability to defer gratification and control behavior
Superficial charm and glibness
Irresponsibility and a failure to accept responsibility for their actions
A grandiose sense of their own worth
It would seem to me that we'd be better served studying what makes an individual a psychopath and go from there. Attractions might be interesting, and might give us a better understanding of why attractions to one sex, age group, race, etc occur, but the criminality of such attractions is what we are more concerned with.
Personally, I don't care if someone is attracted to trees, as long as they don't burn down the forest in some kind of "If I can't have you, no one can", kind of psychodrama. It's not the attraction, it's the criminal impulse that should concern us.
The attraction of a full grown man to a 11-13 year old girl is not that unusual. Girls that age were married off throughout world history, and no one thought it was criminal behavior to have such an attraction. The same is probably true of young men being desire by grown men. The attraction hasn't changed, the laws regarding what is acceptable and what isn't have changed. The attractions have probably always been there.
BTW, I'm not suggesting that because an attraction to 12 year olds exists it should be acceptable. Children cannot give informed consent, and without consent [imo] it is illegal. I'm also not saying that because the Greeks recognized the man/boy attraction and it was legal, that they were more enlightened. I don't think that at all. I'm just illustrating that the attractions alone are not unusual.
I'm also pointing out that as laws and social mores changed the majority of people adapted to the changes. Attractions still occurred, but fewer and fewer acted on their attractions. What makes one man [or woman, I'm not singling out men here, just don't want to keep writing down all the gender identifiers] adhere to changing laws and another man disobey? I think better answers can be found in looking at studies being done on psychopathic behavior, instead of just looking at what some men or women are attracted to...
Just my 2 cents...