Don’t look for a unique human quality of “good” or “bad”, or “good” or “evil”, instead look for degrees, a scale, of “strength” and “weakness” in people.
A strong person is generally balanced in their life; prefers order and organization in their family, but from within, not foisted on them by others; they generally treat people with respect, and trust character more than wealth, power or ambition, yet have little tolerance for bad behavior, criminality or perversity.
They also tend to be self-reliant; serious about their work, whatever it is; and they are comfortable with their lot in life.
A weak person, on the other hand, is a mess. They tend towards neuroses and addiction; they are filled with feelings of anger and hate, envy, greed, lust and spite; they are abusive to others and themselves; they see other people not as individuals but as groups, easy to label; they are grasping for illusory ends, such as wealth and power, control over others; and petty vindictiveness for slights, real or imagined. They are sure of themselves without justification, and they have deep feelings of inadequacy which manifests itself with efforts to feign superiority.
A weak person is generally miserable, no matter where they are or what they do. They feel unloved, and in truth are often unloveable; they feel cheated and that success comes not from hard work, but from luck. Finally they feel that by tearing others down, they lot will improve, or at least they will feel better.
A strong person is only that way if his parents taught him to be when they were stronger and could force him to learn their rules.
There is no evidence in nature or history that a person would grow up in his/her own with those characteristics.
Interesting take on it.
I think a careful examination will also find some mix of good and bad (strong and weak) in everyone.