The human brain works essentially on social conditioning, ethics, morality, language, culture, behaviour, none of these things are inherent. This means nobody is born a moral agent, and that often rather than gaining a sense of morality via objective thought or philosophy humans learn it from social conditioning and essentially what they've been told by those before them. This ability for the human brain to act as a computer system awaiting programming makes for an extremely versatile subject, as well as one vulnerable to manipulation, you take a child to church, you condition them, you teach them mummy and daddy loves them, you condition them, you teach them a thing is wrong or punish or humiliate them, you condition them, it is inescapable. Human kind has no fixed culture, it is all conditioning, the laws of today just like many things are so deeply ingrained into our conditioning that they are rarely questioned, the idea that there is some higher person, a great teacher or authority who knows best is ingrained by our hierarchical system, unsure of our own path we may seek a direction handed down by someone else who supposedly knows better, a doctor, an officer, a law maker, a teacher, a boss, we are not taught to be of strong and independent minds capable of questioning the established order merely taught that it knows best.
The democratic liberal values of today for example are very different from the days say of the Aztec civilisation, when it was believed that carrying out brutal murders would appease the gods, but in many ways it is not so different; The idea that killing to appease gods didn't come from nowhere, it came from someone who claimed that, and without questioning people went along with it, as it is today with authority, as it was in the holocaust and the Stanley Milgram experiment, still today people believe in their laws, their institutions, their media made fairy tales, and why? - Because they've been conditioned to believe, and questioning what they've believed their entire lives to be true is unnerving, so they choose ignorance, believing that there is some great plan, some direction, somebody up there who cares, they swallow the pills they're given, go to work, pay taxes, believe what they're told on the news, they obey the law, they comply for their masters, because they've been conditioned too.