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Willpower may
be a lifelong trait

By Laura Sanders

Forty years after succumbing to a mouthwatering marshmallow as a child, middle-aged adults still have a hard time resisting temptation, a new study finds. The results, published in the Sept. 6 Proceedings of the National Academy of Sciences, suggest that willpower is stable over a person’s lifetime.

“I’m impressed,” says psychologist and neuroscientist Bernd Figner of Columbia University, who wasn’t involved in the experiments. “It really is a unique study.” The experiment began in the late

1960s at Stanford University’s Bing Nursery School, where more than 500 4-year-olds were given the dreaded “marshmallow test.” The preschoolers sat in a room with only a sweet, gooey marshmallow to keep them company. A child could eat the single marshmallow or hold out for 15 minutes to get two. Some kids couldn’t resist and gobbled the treat quickly, while others held out and doubled their reward.

Study coauthor B.J. Casey of Weill Cornell Medical College in New York City and her colleagues wanted to know whether the holdouts displayed the same kind of willpower 40 years later.

Fifty-nine of the original sub-
jects — now in their mid-40s — came
back for more tests. This time around,
researchers tested willpower in a differ-
ent way: Instead of a marshmallow, the
researchers used feel-good pictures of
smiling faces. “We’ve learned through-
out life that smiling faces are good
things,” Casey says.

Oldest hand axes discovered
African finds offer glimpse of early toolmaking complexity

By Bruce Bower

East Africa has yielded the oldest known
stone hand axes and picks, examples
of what researchers call the Acheu-
lian industry. Acheulian implements
unearthed at Kenya’s Kokiselei site
date to 1.76 million years ago, slightly
older than previous finds, say geologist
Christopher Lepre of Rutgers University
and his colleagues. The carefully shaped,
double-edged hand axes and picks lay
among much simpler tools—sharp
flakes pounded off stones, the scientists
report in the Sept. 1 Nature.

hand-ax making, Lepre says. Homo erectus, a possible direct ancestor of modern humans, made Acheulian tools and perhaps Oldowan ones as well at Kokiselei, his team suggests.

“If Acheulian tools gave hominids an edge in Africa, then perhaps groups lacking that technology were forced to find resources elsewhere,” Lepre says.

In line with that proposal, other researchers have unearthed H. erectus fossils at Dmanisi, a West Asian site as old as Kokiselei, along with simple chopping stones, but no hand axes. It remains unsettled whether H. erectus, which first appeared around 2 million years ago, evolved in Africa or Asia.

Some sets of Oldowan and Acheulian artifacts look very similar, implying that the same hominid species could have produced both tool types, says Naama Goren-Inbar of the Hebrew University of Jerusalem.