In September 1979, the psychologist Ellen Langer took a group of frail, elderly men on a week-long retreat, during which she asked them to live as if it were 20 years earlier. The men stayed in a converted monastery, which Langer furnished in a 1950s style; they listened to 1959's music (Hank Williams, Nat King Cole) and 1959 sports games on old-fashioned radios. They weren't allowed to talk about anything that happened after September 1959.
Instead, Langer organised discussions on "recent" events and "new" books, such as Philip Roth's Goodbye, Columbus; she screened Some Like It Hot. Participants who'd become dependent on carers were encouraged to dress, clean and serve meals as if they were younger. By week's end, Langer's dizzyingly audacious hunch had been confirmed. The men were standing straighter, walking better, and demonstrating more joint flexibility. They had stronger grips and better hearing; they scored higher in intelligence tests. (They outperformed a control group, who'd been on a parallel retreat without the time-travel aspect.) In turning back their psychological clock, it appeared, Langer had turned back their physiological one, too.
Langer's study hasn't yet revolutionised healthcare, but the film rights to Counterclockwise, her new book looking back at the research, have been bought by Jennifer Aniston, so maybe that's almost as good. (Details are scant, but I'm imagining Aaron Eckhart as the love interest, working down the hall from Prof Aniston; could Jack Nicholson refuse a cameo as a spritely senior?) Meanwhile, though the original work had its limitations, subsequent research has bolstered the notion of "social clocks", whereby our bodies conform to what we think is appropriate to our age. Women who marry much younger men live, on average, longer than those who don't, perhaps because their clock gets recalibrated. Women who give birth later in life live longer than younger mothers, too: is it because they're surrounded by younger environmental cues - their children - relative to their own age? And men who go bald young, I'm personally distressed to learn, seem more susceptible to certain diseases that can't be explained by the hormones that cause hair loss. Could it be that we early-onset baldsters come to think of ourselves as older, thereby winding our clocks forward?
This is speculative stuff, and speculation on the mind-body connection demands caution: one false move, and you're in "think happy thoughts to cure cancer!" territory. But Langer, a Harvard professor, is no kook. And the broader point - that we're depressingly susceptible to subtle environmental cues, in ways we never notice - is beyond much doubt. Researchers call it "priming": the way people tidy up more thoroughly when they can smell cleaning liquid; or the way students asked to play an investment game behave more competitively when there's a briefcase visible on a table, symbolising business, than a rucksack.
If such cues do affect our bodies as well as our behaviour, Langer warns, we must stop abdicating responsibility for our health to doctors, and stay mindful of how we're letting ourselves be defined. Who says your current energy levels are "just the way you are", or that your aches are inevitable at your age? "Asking why we can't become better even when we feel we are at our best and our healthiest," Langer writes, "is the only way we will ever know how good we can be."