Answer:
Exchange theory
Step-by-step explanation:
According to the exchange theory, all of the interaction that made by individuals will always be based on cost-and benefit analysis. People will only interact if we feel that the benefit from the interaction will outweigh the expense/sacrifice.
When we use this theory to observe family conflict, the family members will most likely compared the situation that they have over other members in a way that benefit them the most. It is very likely for them to see that other family members have better condition/treatment to the point that they became self-absorbed and develop false sense of superiority over the other members.