i tried to reply to this yesterday until i accidently knocked myself offline...
i have a 3 yr old boy as well and a 19 mos old girl. my son (timmy) has always been very agressive. my husband and i have always thought that he got it (genes) from my husband. don't get me wrong, he's not a violent...
i don't have any really large birthmarks, and i really don't think i was actually born with any, but then when i did get a little bit older i got one. a lil tiny red one right next to my index finger knuckle on my left hand. at first i had thought maybe i had burned myself but it never went away...