Well, the idea that we are predetermined FROM BIRTH to be evil or good is a notion that is truly ridiculous. Think about it, did hitler come out of the womb spouting anti-semetic propoganda? The guy grew up as a freaking art student. It wasn't until later in life that he developed certain biases and predjudices.
If you were evil from birth, then it simply couldnt be something psychological. If the term "tabula rasa" is anything to go by, then surely someone who has spent about 5 seconds out of the womb can't be accused of having an evil conscience or praised for having a particularly philanthropic nature. The fact that it couldn't be psychological indicates that it must be BIOLOGICAL, or at best determined later psychologically. If it IS biological then it can be tested, linking evil to a genetic or chemical origins. Either way, the only possible way we could be evil/good from birth is through "fate".
That's not to say it's not possible that we can be evil/good from birth. The same works the other way around; just because a person is brought up in a hovel by abusive parents doesn't neccessarily mean that the child WILL be evil, and visa-versa, being brought up in a life of philanthropic luxury will not always a saint make.
The problem is that anything to do with this sort of argument is subject to two crippling problems: Determinism and Cultural differences. Either way you look at this (unless you take a neutral side) it's heavily steeped in determinism: it's either, "you WILL be evil/good from birth" or "However you are brought up, it WILL mean you will be evil/good". Both notions may or may not contain some weight, but neither of them allow for any amount of freewill, and ignore a persons emotional capacity to do acts of both. Secondly, the terms "evil" and "good" carry different meanings in different places. Some acts of "evil" in the western society may not carry over to other places, or even to other social groups in the SAME PLACE (i.e. Morbid humour in some groups is encouraged, while in others damned, thus the label of appropriateness is changed over the space of a playground). Some people view the active predjudice of homosexuals as something to be appaled at, but in some places they view it as the work of god himself, to them what could be more good than to do gods work?
Also, while on the subject of the... subjectiveness of good vs evil, you must also consider the idea of black-and-white or shades-of-gray. Are all "evil" acts just as bad as each other? In which case someone who is forced into a situation where he has to do a bad thing for a good reason could be just as damned as someone who does a bad thing because he or she feels like it. Again, but the other way around, if someone does good for a selfish (bad) reason, (say gives help to someone else, just to rub it into the face of another person) can they also be considered good? On the other side of the coin (a far more likely side) is it possible that good and bad deeds can fall onto a scale of right and wrong? The point is, good/evil, right/wrong as just words associated with social biases.
TL;DR?
-Feasable both ways potentially, much more likely NURTURE than NATURE.
-Both views are deterministic, not a lot of room for emotion/free-will.
-Good/Evil highly subjective culturally.