Kids are proving more patient than ever.

Science News shows how the marshmallow game – give a pre-teen one marshmallow now or let them wait, staring at it, for n minutes to get two later – is changing over time. Today’s children, it turns out, are able to delay gratification for a bit longer:

This willingness to delay gratification has recently bloomed among U.S. preschoolers from predominantly white, middle-class families, say psychologist Stephanie Carlson of the University of Minnesota in Minneapolis and her colleagues. Youngsters aged 3 to 5 in the 2000s waited an average of two minutes longer during the marshmallow test than children in the 1960s did, and an average of one minute longer than 1980s kids did, the scientists report June 25 in Developmental Psychology.

…[T]he new findings don’t address whether youngsters’ willingness to delay gratification in the lab translates into an ability to resist everyday temptations, says study coauthor Walter Mischel of Columbia University, the psychologist who directed the first marshmallow tests in the 1960s.

In the new study, the team analyzed and compared data from three groups of 3- to 5-year-olds: 165 kids who completed the marshmallow test between 1965 and 1969, 135 who did so between 1985 and 1989, and 540 tested between 2002 and 2012.

The average amount of time kids were willing to wait for a treat increased in each generation — from about five minutes in the ‘60s to six minutes in the ‘80s and seven minutes in the 2000s. That trend was observed among both boys and girls, younger and older preschoolers and kids in different parts of the United States.

It’s not known if the same trend applies to kids from poor and nonwhite families. Some previous evidence suggests children on the lower end of the economic scale often choose an immediate but lesser treat on the marshmallow test, Carlson says. That behavior may make sense if children live in unpredictable settings or don’t trust adults who promise future treat bonuses