There are only two ways to acquire morality: 1. Genetic - we are born predisposed to learn what morality is and learn it quickly (except people with mental problems). Most likely we have a compartment in our brains dedicated to morality. Same as with speech, learning and understanding speech for humans is easy, because parts of our brains are dedicated to it. Obviously, morality was essential to our evolutionary past, therefore it exists. The only universal aspect of morality is that it might be common to all or most group animals.
2. Learned - most of our morality standards come form influence of our societies. We know from history and from ways of life of different ethnic groups that standards of morality change, but all of them have one. Obviously it must be the nurtured component.