Humans are restrained constantly.
Their parents would keep them protected when they were children, weak and ignorant. Their family controlling every word and every action they made—such as prohibiting them from entering deep waters, touch fires or approaching strangers—the most fundamental rule set for safety.
Their teachers and significant others would instruct them in the principles of self-conduct as they interacted in the halls of learning when they were youths. They would learn that others were bodies no different themselves, with moral standards that varied depending on the individual gradually marked down in their hearts and becoming the cornerstone when they enter society later.