The budget airline AirTran used to air a funny commercial about a couple of grandparents visiting their progeny shortly after the birth of their grandchildren. The grandparents were expecting a week together with the whole family. Instead they were handed the babies at the door, while the new parents jumped into a taxi and headed for the airport. “We’ll call you when we land,” says the new mother with a smile. The scene fades with the helpless grandfather shouting at the departing taxi: “Don’t leave us with the babies! Don’t leave us with the babies!”
Few parents are quite as ruthless as this, but it’s not news to anyone, least of all grandparents, that their children are apt to treat them as free child minders. According to the U.S. Census, about a quarter of children under 5 get handed over to the grandparents part of the time. In the U.K., astonishingly, about 40% of grandparents look after their grandchildren regularly, in the overwhelming majority of cases at least once a week.
Parents in these cases may assuage their consciences by insisting that the experience is good for the grandparents. There are indeed studies which find, or claim to find, that grandparents who look after their grandchildren are healthier, happier, and physically more fit as a result.
Phooey, report researchers Peter Eibich and Xianhua Zai of Germany’s Max Planck Institute for Demographic Research. These findings are bogus, rely on fundamental logical errors, and involve the basic mistake of confusing causation and correlation. After studying nearly 20 years’ data for more than 20,000 older Americans, they conclude that looking after the grandchildren does not benefit the grandparents. On the contrary, there is some possibility it does harm. “Our results indicate that the effects of grandparenting on health are not significant and, in some instances, [are] negative,” they report.
The previous findings, they point out, are skewed by an obvious problem: Selection bias. Grandparents who are fit, physically and mentally, are most likely to be asked to act as childminders. That doesn’t mean that looking after the grandchildren makes them fitter.
You might just as well argue that being asked to play for, say, the Boston Celtics makes you taller.
Eibich and Zai tried to control for this effect by introducing other factors, such as the number of children and their sex, which also have a strong correlation with whether or not you are likely to end up looking after grandkids. (All other things being equal, parents of daughters are more likely to become grandparents early than parents of sons, and are more likely to be actively involved in helping raise their grandchildren.)
After accounting for these controls, they find, the supposed positive health benefits of looking after the grandchildren vanish.
Naturally, as the researchers admit, there are limitations to the broad conclusions. A previous study in Europe, for example, found that looking after the grandkids was stressful for grandparents. The health effects, if any, were negative. But another one, a decade ago, in Taiwan found the opposite. The grandparents seemed to benefit.
Among the potential other factors may be how the elderly are treated more generally. It is possible the grandparents get a benefit if they are included more broadly as part of an extended family. But maybe they don’t enjoy being kept at arm’s length until they are wanted as free labor.
If so, they aren’t completely without the means of redress. One option is to leave some, or all, of their estate to children who need it more. They can ease their conscience by reflecting that they have, after all, spent their golden years giving their own children lots of free labor instead.