This question refers to the lynching of Emmett Till.
This question refers to the moment in which Till was flirting with Carolyn Bryant. Although Till believed that his actions were relatively harmless, the older man warned him against them, as he knew they could lead to trouble.
This older man was a local, so he understood the social rules that regulated interactions between black and white people in the South. He knew how these interactions often led to problems for black people. He most likely learned the rules through the process of socialization that he engaged in from the moment he was born. They were passed down to him through his parents, friends, relatives, neighbours, etc. These rules are often enforced in a social way, not through law, but through the actions of the community. In this case, they were enforced through violence and murder.
