For longer versions of these and other
Humans stories, visit www.sciencenews.org
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
Fossils are needed to confirm that
H. erectus made both kinds of implements at Kokiselei, says John Shea of
Stony Brook University in New York.
P.-J. TEXIER, © MPK/WTAP