Experiments have borne out Wegner's theory. One group of researchers studied older couples who'd been together for decades. When separated and questioned individually about the events of years ago, they'd sometimes stumble on details. But questioned together, they could retrieve them. How? They'd engage in "cross-cuing," tossing clues back and forth until they triggered each other. This is how a couple remembered a show they saw on their honeymoon 40 years previously:
F: And we went to two shows, can you remember what they were called?
M: We did. One was a musical, or were they both? I don't . . . no . . . one . . .
F: John Hanson was in it.
M: Desert Song.
F: Desert Song, that's it, I couldn't remember what it was called, but yes, I knew John Hanson was in it.
They were, in a sense, Googling each other. Other experiments have produced similar findings. In one, people were trained in a complex task — assembling an AM/FM radio — and tested a week later. Those who'd been trained in a group and tested with that same group performed far better than individuals who worked alone; together, they recalled more steps and made fewer mistakes. In 2009 researchers followed 209 undergraduates in a business course as they assembled into small groups to work on a semester-long project. The groups that scored highest on a test of their transactive memory — in other words, the groups where members most relied on each other to recall information — performed better than those who didn't use transactive memory. Transactive groups don't just remember better: They also analyze problems more deeply, too, developing a better grasp of underlying principles.
We don't remember in isolation — and that's a good thing. "Quite simply, we seem to record as much outside our minds as within them," as Wegner has written. "Couples who are able to remember things transactively offer their constituent individuals storage for and access to a far wider array of information than they would otherwise command." These are, as Wegner describes it in a lovely phrase, "the thinking processes of the intimate dyad."