Because answering back is actually doing your angsty son or daughter a favour.
According to research, argumentative teenagers fare better in adulthood than those who are more placid.
The logic goes that arguing gives teenagers confidence and negotiating skills.
And those who regularly fight verbally with their parents cope better with peer pressure and are less likely to abuse drugs or alcohol.
They are also more skilled negotiators and can "learn to be taken more seriously" after some verbal jousting with their elders.
The study, in the U.S. Child Development Journal, concluded that parents should consider actively starting rows with their teenagers just to hone their youngsters' skills – even if it does result in an ear-bashing in the short term.
University of Virginia psychology professor Joseph Allen, lead author of the study, said: "It turns out that what goes on in the family is actually a training ground for teens in terms of how to negotiate with other people."
And so, to non-scientifically test this scientific study, I ran the theory past my own Tween stepdaughter. Her response: "Oh per-lease. Get a life!"
More on Parentdish: Our must-read weekly column Surviving Teenagers