There's a very interesting article in Quartz titled 'Your college major is a pretty good indication of how smart you are'. Here's how it begins.
Do students who choose to major in different fields have different academic aptitudes? This question is worth investigating for many reasons, including an understanding of what fields top students choose to pursue, the diversity of talent across various fields, and how this might reflect upon the majors and occupations a culture values.
In order to explore this, I used five different measures of US students’ academic aptitude, which span 1946 to 2014, and discovered that the rank order of cognitive skills of various majors and degree holders has remained remarkably constant for the last seven decades.
An important caveat: The data presented looks only at group averages and does not speak to the aptitude of specific individuals. Obviously there are people with high academic aptitude in every major and there can be larger aptitude differences between entire schools—for example the University of Chicago and a local community college—than between majors within a school. Also interests, which are not directly assessed here, likely play an important role in which major someone selects. One could argue that any one specific test and sample may not be an accurate reflection of the aptitude of specific majors, and this would be a valid point. However, this analysis uses five independent measures and samples of academic aptitude at different points in time—which include everything from tests of cognitive abilities to tests of academic achievement—showing these findings replicate and are quite robust.
There's more at the link.
This also has implications for the current emphasis on science, technology, engineering and mathematics (STEM) qualifications. From the article:
According to a recent Payscale college salary report, STEM majors tend to be the most highly compensated. That STEM majors have consistently had the highest average academic aptitude may also reflect the fact that STEM disciplines are highly complex and require such aptitude. Even scientists in the “hard” STEM fields (e.g. physics, math) tend to believe that these fields require brilliance or genius ... Perhaps the STEM disciplines have always selected on academic aptitude and employers have rewarded that aptitude and skillset due to STEM’s usefulness in a variety of fields.
I found it particularly significant that in studies spanning almost three-quarters of a century, the correlation between IQ and choice of major subject(s) or field of specialization held true. I would have expected automation, the rise of information technology and subsequent, transformative changes in many fields of study might well have required students with a different kind of personality or different aptitudes to master them. Consider that architects, for example, worked with pens and pencils and drafting boards in 1946, whereas today everything is computer-based. I would have thought that change would require different and/or additional competencies. It seems that wasn't the case.
On the other hand, the military is finding that young entrants who are skilled in computer games are able to adjust much more quickly to high-technology equipment and the new tactics it enables. Drone piloting, for example, is a skill the Army is imparting to tech-geek soldiers, with considerable success. However, until very recently the USAF had resisted training non-pilot-qualified personnel to operate drones. I understand that's changing now, partly due to the Army's proven track record, partly due to a shortage of pilots willing to accept the change in career path that UAV operations entail. Does this mean that to be a soldier today is somehow different from what it was in the past? I beg leave to doubt that. IQ has never been the determinant of a warrior, although more intelligent warriors might tend to last longer in combat. The physical demands of that environment, and the necessity to kill one's opponent, can't be automated - or, if they are, when the batteries run dpwn, it'll be back to the same old, same old!