good eats looms large, says biologist
Philippe Louâpre of the University of
Rennes in France.
With each discovery of a sphere,
92 volunteers reported becoming
increasingly motivated to open more
chests in the same dome. As empty chests
accumulated, the volunteers reported a
growing desire to move their search to a
new dome. Players reacted more strongly
to finding a sphere than to opening an
empty chest, enabling them to zero in on
clumps of orb-bearing containers but also
leading them astray if they found the only
orb in one part of a dome first.
Participants searched domes in this
way whether spheres were distributed
randomly, evenly or in clusters, Louâpre
and his colleagues report in a paper published December 8 in PLoS ONE.
Other evidence indicates that bumblebees searching for pollen-bearing flowers
and parasitic insects seeking host animals
In a computer game, volunteers tended
to use a patch-finding strategy to search
domes for chests containing green
spheres (game order, top to bottom).
Images at leFt: louÂpre et al/plos one 2010; Images at rIght, From top: harrIs & ewIng/lIbrary oF
Congress; lenny IgnelZI/assoCIated press; IrIsKawlIng/wIKImedIa Commons; nFl/assoCIated press
take the same simple approach in deciding whether to keep looking in the same
place or go elsewhere, Louâpre says.
“There may be an ancient motivational mechanism tailored by natural
selection for deciding when to leave a
patch,” he says.
Such findings are intriguing but don’t
confirm that people have evolved to
expect sequences to be streaky, remarks
psychologist Thomas Gilovich of Cornell
University. Slot machine and video game
players may simply reason that clusters
of icons or green orbs in a small, random
sample represent the pattern that can
be expected in a much longer sequence,
Gilovich argues. A biased sample could
prevent players from recognizing that
icon and orb distributions would eventually even out.
Gilovich first proposed this explanation in an influential 1985 paper. Using
shooting and free throw records over
one to two seasons of play for two professional basketball teams, he and his
colleagues found no chance-busting
sequences. Yet 91 of 100 basketball fans
surveyed by the researchers believed
that players get hot hands, defined in the
study as a player having a better chance
of making a shot after making his last two
or three shots than he does after missing
his last two or three shots.
Some hot hands do appear to be real.
Studies have found hot hands in individual sports — such as golf putting, bowling
and horseshoes — in which players largely
avoid the influences on one another that
affect performance on a team. And a 2000
computer simulation of basketball shots
over a season suggests that the statistical tools employed by Gilovich may have
missed some genuine hot-hand scoring
runs among hoops players, Wilke says.
Just remember: Casino slot machines
are called one-armed bandits for a reason. The only streak to expect by feeding
them money is a losing one. s
s For more resources on streak psychology, visit andreas wilke’s lab website:
Famous sports streaks
In professional sports, amazing streaks get
celebrated as demonstrations of athletic
prowess and heroism. whether these grand
acts of sustained achievement surpass
mathematical standards of randomness
or not, each one inspires new generations
of players and fans alike with a story of
almost unbelievable achievement.
56-game hitting streak
where have you gone,
Joe dimaggio? look in
the record books. Joltin’
Joe got at least one base
hit in every game from
may 15 to July 16 during the 1941 season.
during his streak, the
yankee Clipper had a
batting average of .408
and added a hit in the all-star game. pete rose
comes in a distant second to dimaggio, with hits
in 44 consecutive games in 1978.
Pitched 59 scoreless
innings in a row
the right-handed pitcher,
finished the 1988 major
league season with an
amazing streak, leading
the los angeles dodgers
to a world series win
over the oakland a’s. he
bested by one-third of an
inning a record set in 1968 by the dodgers’ don
drysdale. during hershiser’s streak, he allowed
30 hits, walked nine batters and struck out 34.
51 consecutive games
with a point
Known as the great one,
gretzky tallied either a
goal or an assist in each
of the edmonton oilers’
first 51 games in the
1983–84 hockey season.
In doing so, gretzky broke
his own record from the
previous season of 30
straight games with a goal or assist. the streak,
which included 61 goals and 92 assists, set a
record that has lasted more than a quarter century.
47 consecutive games
with a touchdown pass
From 1956 to 1960, the
baltimore Colts quarter-
back threw a touchdown
pass in 47 straight
games. unitas estab-
lished a streak that has
held up even against
today’s elite quarter-
backs, such as peyton
manning and tom brady. unitas dismissed his
record as unimportant and said that he cared
only about winning games. — Bruce Bower