http://www.udel.edu/educ/gottfredson/reprints/1997whygmatters.pdf

why g matters: the complexity of everyday life

excerpt:

World War II offers an early demonstration. During a period when it had to
train many thousands of pilots, the military experimented with admitting to pilot
training inductees of all ability levels (Matarazzo, 1972, p. 163). Of men in the
top stanine of the experimental selection battery, which included abilities and motivation measured at induction, 95% successfully completed training, whereas
only 20% of those in the lowest stanine did so. Subsequent military research has
consistently shown that highly g-loaded measures such as the Armed Forces Qualifying
Test (AFQT) and its forerunners, although not always conceptualized as
measures of g, are good measures of “trainability’‘-hence their long-time use in
screening for enlistment and assignment to training programs. More recent work,
such as Army Project A (McHenry et al., 1990), has carefully demonstrated the
validity of such measures for predicting job performance itself in military specialties.

Additional evidence of the causal importance of g is provided by the many unsuccessful
efforts to eliminate or short-circuit its functional link (correlation) with
job proficiency. For example, there have been efforts to train the general cognitive
skills that g naturally provides and that jobs require-such as general reading
comprehension (which is important for using work manuals, interpreting instructions,
and the like). Another approach has been to provide extra instruction or
experience to very low-aptitude individuals so that they have more time to master
job content. Both reflect what might be termed the training hypothesis, which is
that, with sufficient instruction, low-aptitude individuals can be trained to perform
as well as high-aptitude individuals. The armed services have devoted much research
to such efforts, partly because they periodically have had to induct large
numbers of very low-aptitude recruits. Even the most optimistic observers (Sticht,
1975; Sticht, Armstrong, Hickey, & Caylor, 1987) have concluded that such training
fails to improve general skills and, at most, increases the number of lowaptitude
men who perform at minimally acceptable levels, mostly in lower level jobs.


Not even lengthy experience (5 years) eliminates differences in overall job
performance between more and less bright men (Schmidt et al., 1988). A large
study of military cooks, repairmen, supply specialists, and armor crewmen showed
that performance may converge on simpler and oft-performed tasks (Vineberg &
Taylor, 1972, p. 55-57). However, even that limited convergence took considerable
time, reflecting large differences in trainability. It took men in the 10th to 30th
percentiles of ability about 12 to 24 months to catch up with the performance levels
on those tasks that were exhibited by men above the 30th percentile with no more
than 3 months’ experience on the job. These findings from field settings are consistent
with Ackerman’s (1987) review of the experimental literature relating skill
learning and ability: individual differences in performance do not decrease with
practice, and sometimes increase, when tasks are characterized by “predominantly
inconsistent or varied information processing requirements .” In short, tasks that are
not easily routinized continue to call forth g.

probably. maybe people in america just had enough g to figure out the whole thing was a waste of time so they protested nixon to bring the troops home!

Are whales less or more intelligent than humans? How to ascertain this objectively?