Lacey Von Erich is a third generation wrestler to her father and grandfather. It's like the army or the police force. "My father was a wrestler. My father's father was a wrestler. My father's father's father's father's father's father's father was a wrestler too. He wrestled wooly mammoths." Whatever high they get from wrestling must also affect the children, because we see many wrestlers have wrestling children. Let's do some scientific work to find the wrestling gene.
I bet the wrestling bug especially affects people with two wrestling parents more than just the one. Think about it. If your parents were both accountants, you wouldn't really register that there are other ways to make a living. It would always make sense to be an accountant. If both your parents are wrestlers it probably feels stupid to go into an office job.