The argument’s conclusion is that children’s problems aren’t necessarily caused by difficulty adjusting. The assertion that children of divorced parents have more problems is just given as a fact; it isn’t supported by anything, so can’t be a conclusion.

The researcher accepts that children of divorced parents have more problems. The argument is instead trying to refute the idea that the problems are caused by difficulty adjusting to the divorce.

The researcher never claims that divorce is harmful to children. If anything, the argument implies that problems are caused by the parents’ pre-divorce behavior, not the divorce itself.

The claim that certain behaviors can lead to divorce is presented as a fact without any support. Also, the claim about children of divorced parents having psychological problems doesn’t support any other claim in the argument: it’s context.

This is the role played by the claim that children of divorced parents have more psychological problems. It’s taken as a fact, and the researcher explains it with learned behavior.