We are not born with a desire to crush others underfoot and only think of ourselves, but many societies breed that now. We're taught that everybody is competing for a finite number of spots at the top of the ladder and you do what you have to do to get one. We're far from pure by the time we've reached adulthood but we don't start that way.
If man were inherently evil then the species would not have survived this long as we all would have killed each other by now. Man is a weak animal and members have had to bond together from the beginning just to survive. The self serving evil members were ran out of the tribe and subsequently became extinct due to natural selection.
Man is inherently good because it is in Man's best interest to be good. When a person is kind to another person, it opens up for the other person to be kind to others. There will be people who take advantage of this kindness, but, as a whole, mankind is good to each other.
Supposedly evil means someone who is immoral. The very idea of morals was created by humans- a set of rules that when adhered to would allow the existence of society. Before a child is taught about morals by parents, teachers and ,society in general, a child is most likely neither good or bad. So what determines whether a person adheres to their personal moral code: their experiences in life, including their parents' beliefs and their time at school and work.
It may be that we aren't born with a desire to kill or manipulate, however it does not necsessarily therefore follow that we are born with the desire to help others and be absolute saints.