Sadly, Eliza, I don't know what it is but I doubt it is chemical. I have the same feelings and urges as other men, I think, although at approaching 70 they have lessened! Certainly as a younger man there were times when it was a good job it was not a crime to fantasise :-) I was brought up in the era when sexism, and racism for that matter, was acceptable. Yet for all that the very thought of taking advantage of anyone by force repulses me. Why some men act on those base impulses is beyond my limited reasoning :-(