Moral Compass

Conscience is the word you are looking for. The Oxford dictionary defines it as "an inner feeling or voice viewed as acting as a guide to the rightness or wrongness of one's behavior." Why does this voice exist? I am not sure if it is instilled in us at birth, or if it needs to be taught to us at an early age. It seems it may have a relationship with empathy, which is to feel another's feelings as if they were our own, and it seems to be something that is lacking in the minds of cold blooded killers, or other perpetrators of cruelty who act with supposedly no remorse. I would be interested in learning the definitions of this word in other languages. I am curious to find if other cultures have any variations as to the origin or explanation of this word "conscience".