Right and wrong are subjective in how they relate to suffering. It feels bad to suffer. If we have empathy, we don’t want to impose suffering on others, including animals. We don’t want to have the memory of making someone suffer. It feels wrong and therefore it is wrong. It feels bad to do wrong things and these feelings, how strong they are, depend on the individual.
Psychopaths do not have this feeling of right or wrong. They do not feel empathy for the beings they harm. They also have no feelings of love or compassion for themselves. In that sense, too, right and wrong are entirely subjective. Feeling bad when we do wrong things is what keeps people in line, even more than the fear of being punished by the society that makes the rules.