Tensions among in-laws often arise from an inescapable fact of extended-family life. As psychologist Terri Apter puts it: “You don’t choose your in-laws; you choose your partner.” And this usually means that accommodations are needed in three areas.

New Ways of Relating: “With your own parents, you can shout, you can complain, you can say that you’re hurt,” says Apter. However, “you don’t know your spouse’s family’s rules about what can and can’t be said — and that is where much of the stress comes from.”

New Roles: “Parents often feel they ought to be like a tribe’s council of elders, and that children should come to them for advice,” says author Alicia Fortinberry. “The younger couple wants to make it on their own and doesn’t want the advice from the in-laws, who then get hurt when advice isn’t asked for.”

New Expectations: When a couple gets married, both sets of in-laws often feel the new family is an extension of their own. “A conflict of loyalty occurs, and the in-laws may sense it as competition,” says psychologist Bob Murray. “‘You see the other family more than you see ours.’”