For example the part of us that suffers along with those we see suffering; the part of man that risks his own life to save others, etc. The examples of inate goodness are as vast as those of inate evil. I happen to think that they are hard wired. The hard wiring is susceptible (sp?) to corrosion no doubt, by both physiological and psychological degradation, but I think it's there nonetheless.
One of the things that argues for your point of view, in my opinion, is that to the best of my knowledge there is no historical secular equivalent to Mother Teresa or Damien the Leper. My point being that the development of the better part of man, via secular inducements, doesn't seem to be as efficacious as it does with God centered inducements.