428 Iv. COGNITI vE AND M OTIvATIONAL P ROCESSES
Genius
The term genius  has a much longer history 
than that of creativity.  In fact, the word 
originated in the times of ancient Rome, 
when each person was believed to be born 
with a “guardian angel.” Yet beginning with 
Galton’s 1869 Hereditary Genius,  the term 
found its way into the behavioral sciences. 
The word then began to accrue a more ob -
jective and quantitative meaning. Eventual -
ly, psychologists proposed two contrary op -
erational definitions of the construct—  the 
psychometric and the historiometric.
Psychometric  Definition
Galton (1869) conceived of genius in terms 
of the normal distribution of what he called 
“natural ability.” Those individuals whose 
natural ability placed them in the remote 
upper tail of the bell-  shaped distribution 
were identified as geniuses. Unfortunately, 
Galton’s conception of genius could not be 
directly implemented until the advent of the 
intelligence test. These tests were used to 
label children as intellectually gifted. Pio -
neers such as Lewis Terman (1925) and Leta 
Hollingworth (1942) helped to establish the 
practice of styling a child a “genius” if he or 
she scored above a certain set level on some 
standardized IQ test, such as the Stanford– 
Binet. Later, when adult intelligence tests 
emerged, this psychometric definition was 
carried over with minimal modification. 
A genius was simply a child or adult who 
scored above some predetermined level.
Often the cutoff was put at IQ 140, a hy -
pothetical threshold that has found its way 
into many dictionaries and encyclopedias 
(e.g., American Heritage,  1992). Others 
would relax the criterion somewhat. For in -
stance, the Mensa Society sets the figure at 
two standard deviations above the popula -
tion mean, which results in a requirement 
of around 132 on many tests. Naturally, 
because scores on IQ tests can be consid -
ered interval variables, genius can be also 
conceived in a more continuous fashion. It 
is then possible to speak of relative degrees 
of genius. Indeed, this very practice has in -
spired the appearance of additional clubs of 
even more elite intellects. The Four Sigma 
Society requires its members to be four stan -dard deviations above the mean (or around 
IQ 164), while the Mega Society stipulates 
an IQ only obtained by one in a million (or 
around IQ 176).
The psychometric definition of genius en -
joys the advantage that the best intelligence 
tests stand among the most reliable of all 
psychometric instruments. That said, psy -
chometric genius also encounters problems 
when it is extended to the domain of creative 
achievement (Simonton, 2016). A concrete il -
lustration is seen in Terman’s classic Genetic 
Studies of Genius  (Terman, 1925–1959). 
Having selected more than 1,500 children 
on the basis of exceptional IQ scores, Ter -
man conducted a longitudinal study to de -
termine whether these young geniuses would 
grow up to become highly accomplished 
adults (Terman & Oden, 1959). Although 
many attained considerable success, it is fair 
to say that none achieved the highest lev -
els of acclaim. For example, there were no 
Nobel laureates among the group. The iron -
ic fact eventually emerged that among those 
screened in the early 1920s were two chil -
dren who grew up to earn Nobel Prizes in 
Physics, namely, William Shockley in 1956 
and Luis Alvarez in 1968. Yet their child -
hood IQs were not high enough to get either 
one of them included in Terman’s elite sam -
ple (Winner, 1996). Although Terman’s lon -
gitudinal study continues to this very day, 
it now has become a gerontological inquiry 
rather than a study of genius per se (Duggan 
& Friedman, 2014).
Historiometric  Definition
When Galton wrote Hereditary Genius,  
there existed no psychometric measures that 
could be used to define genius. Therefore, 
Galton introduced a rather different opera -
tional definition, the historiometric (Simon -
ton, 2014b). According to this alternative, 
genius is defined in terms of an individual’s 
contributions to a particular domain of 
human achievement. A genius is then a per -
son whose effects on a domain are so numer -
ous and so distinctive that the domain is ap -
preciably transformed. The most prominent 
geniuses often make names for themselves 
by becoming eponyms for discoveries, move -
ments, or events. Illustrations include the 
Copernican revolution, Newtonian physics, 