User blog comment:Frodo the 9 fingered/A Third Camp?/@comment-3146930-20120726210504/@comment-4531192-20120806232100

The kind of hatred the campers have for each other is not in their DNA, but rather comes from their upbringing. Especially Roman demigods are taught this intolerance towards the Greeks given their history (notably the Trojan war). It is stated in The Lost Hero that gods do not have DNA.