Vacation equation

Vacations aren’t high energy physics. You’d think studying them might be easier than figuring out the origins of the universe.

But the field has its own complexities, says Ken Locke, a psychology professor at the University of Idaho. It’s “influenced by a mess of complex variables, such as who you vacation with (e.g., just one loving partner versus that loving partner and several nagging in-laws), where you go (e.g., a fancy resort versus a disease-infested swamp), why you go (e.g., you choose to do it versus friends badger you into it), and so on.”

Then there’s the problem of experimental design. With vacations, it’s virtually impossible to conduct carefully controlled trials — the gold standard of scientific study. “You can’t randomly assign people to take a vacation or not,” says Ken Sheldon, a psychologist who studies leisure time at the University of Missouri at Columbia.

Thus, most findings about vacations are correlational. We know people are more likely to have heart attacks if they don’t take regular vacations than if they do. But we can’t say they’re more likely to have heart attacks because they don’t take regular vacations.

And no one can really say what counts as a good vacation. Does it have to last a certain amount of time? Does it have to involve leaving home? This may simply be a matter of taste, says Cathy McCarty, senior epidemiologist at the Marshfield Clinic Research Foundation in Marshfield, Wis. “Vacationing,” she says, “is personal.”