The particulars from the new study, which tested Americans’ ability to recollect the names of past presidents, are hardly jaw-dropping: People tend to recall best the presidents who served recently, as well as the first few in the country’s history. They also remember those who navigated historic events, like the ending of slavery (Abraham Lincoln) and World War II (Franklin D. Roosevelt).

But the broader significance of the report — the first to measure forgetfulness over a 40-year period, using a constant list — is that societies collectively forget according to the same formula as, say, a student who has studied a list of words. Culture imitates biology, even though the two systems work in vastly different ways.

The new paper was published in the journal Science.

“It’s an exciting study, because it mixes history and psychology and finds this one-on-one correspondence” in the way memory functions, said David C. Rubin, a psychologist at Duke University who was not involved in the research.