One of the founding fathers of the study
of intelligence, Francis
Galton, was a very interesting and colorful figure.
Galton, who was Charles Darwin's cousin,
wanted to implement Darwin's theories on humans, and to improve humankind by
mating between people with the best mental, moral and physical skills. Nowadays such an idea sounds shocking, but in
the nineteenth century it might have sounded reasonable. Galton looked into
families of people who were considered wise and successful, and saw that the
closer the blood relation to a wise
person is, the better are the chances of this person's
relative to be also wise. Galton deduced
that "wisdom" (the term "intelligence" didn't exist then)
is, at least partly, hereditary. Galton
studied children who were adopted by the Pope, to see what is more influential:
genetics (which was "weak" in these children's case) or environment
(an environment rich with stimuli at the Pope's surrounding). He found that there is an interaction between
genetics and environment, but genetics is stronger than environment.
Apropos Galton, he probably was
the only psychologist in history who was paid by his experiment participants for
this privilege! Galton studied other
things, like women's attractiveness in different parts of England, and the
relationship between prayers for the wellbeing of kings and their life
expectancy (he found there was no relationship…).
While Galton worked in the 19th
century, John Watson, one of the founding fathers of Behaviorism, wrote in
1930: " Give me a dozen healthy infants, well-formed, and my own specified
world to bring them up in and I'll guarantee to take any one at random and
train him to become any type of specialist I might select—doctor, lawyer,
artist, merchant-chief and, yes, even beggar-man and thief, regardless of his
talents…"
Anders Ericsson sided with Watson. In the 1990's he interviewed violinists and
pianists and found that the violinists and pianists who were considered to be
the best of their kind accumulated more than 10000 hours of practice by age 20. Amateur violinists accumulated about 5000
hours of practice and amateur pianists – about 2000 hours of practice by age
20. Ericsson argued that genes may contribute to individual differences
in people's willingness to engage in deliberate practice over a long period of
time, and thus may indirectly contribute to individual differences in
performance, but he explicitly rejected
the view that innate ability can account for why some people become experts and
others fail to do so. He argued that
expert's performance reflects a long period of practice more than innate
ability or talent.
It's easy to see why Ericsson's 1993 paper
on this subject became a hit and was cited more than a thousand times.
Clearly, many people who want to
become experts – as violinists, physicists, athletes and so on – don't make it
despite investing hours of practice and effort.
In this paper:
Deliberate practice: Is that
all it takes to become an expert?
David Z. Hambrick ,
Frederick L. Oswald , Erik M. Altmann , Elizabeth J. Meinz, Fernand
Gobet , Guillermo Campitelli .
Intelligence 45 (2014) 34–45
the researchers asked: is practice enough to become an expert? Can individual differences in performance be
explained mostly by individual differences in practice hours?
They studied these questions by analyzing research done in two
areas of expertise: chess and music.
The chess studies included players who
were rated in the international rating, the Elo, were members of prestigious chess
clubs, participated in national chess programs
and so on. These players gave
information about the age they started playing and estimated the number of
practice hours they had each day during their training years. The authors found that practice explained 34%
of the variance in chess performance (the player's Elo rating). 34% is a significant amount, but practice did
not explain everything! They also found,
that some people needed much less practice to reach an excellent level of performance
in chess. Some expert chess players
needed 3 times more hours of practice than other expert chess players. Some expert chess players needed less practice
hours than intermediate chess players. Some
intermediate chess players practiced more than expert chess players.
The paper describes the story of the
Polgár sisters who, beginning at a young age, received several hours of chess
instruction every day from chess grandmasters and their father, a chess teacher
and author of several chess books. The sisters differed both in the highest
rating they achieved and in the amount of practice they accumulated to reach
that rating. One sister's peak rating was 2735 in an estimated 59,904 h of
practice, whereas another sister's was 2577
in an estimated 79,248 h of practice. The two sisters who became grandmasters had
accumulated a great deal more practice by the time they reached their peak
rating than had the eight grandmasters who reached top-ten in the world with a
mean of about 14000 hours of practice.
Deliberate practice is clearly not
sufficient to account for individual differences in chess performance. What else
explains chess performance? What about excellence in music? These
topics will be discussed in the next post.