How does IQ Affect everyday life & career opportunities?

Your intellectual potential and IQ are significant determinants in how your life unfolds. From your early school years, the ease with which you learn will often determine how much you enjoy school. If you have a low IQ, you may struggle with mathematics and other cognitively demanding subjects, preferring to work with “real objects” rather than abstract ideas. This might prompt you to focus on the trades or on “practical subjects” as you enter secondary school. 

If you have average intelligence, you are more likely to be able to connect socially with most people and share interests with them. If you plan post-secondary education, you will probably choose to study something that does not have heavy mathematical prerequisites. You might aspire to a profession, but if so, you will need to work hard to achieve as well as most of your classmates.

If you are above average in intelligence (IQ ≥ 120) you can pursue almost any profession or field, but you must have a very high IQ to specialize in theoretical physics or mathematics at the graduate level. You will probably not share the same interests as most people, but will find your own group of friends with whom you socialize. 

The figure below from the College Board gives the average SAT score by college major for the year 2014. Since SAT scores have a strong correlation with IQ, this figure provides a rough comparison between IQ and chosen field of specialization. 

Comparing average IQ’s across college majors can be misleading because the variation in IQ’s within a major is much greater than the variation across majors. That is, there is a very wide difference in the IQ’s of students in any particular major, so the person with the highest IQ in a major like education may have an IQ greater than the IQ’s of most of the students in theoretical physics. 

In their controversial, but seminal book, The Bell Curve, Herrnstein and Murray identify those in the “high-IQ professions.” These include accountants, architects, chemists, college teachers, dentists, engineers, lawyers, and physicians. They state:

The mean IQ of people entering those fields is about 120, give or take a few points. The state of knowledge is not perfect, and the sorting process is not precise. Different studies find slightly different means for these occupations, with some suggesting that physicians have a mean closer to 125, for example. Theoretical physicists probably average higher than natural scientists in general.

What about Socioeconomic Success?

In a meta-analysis of the relationship between intelligence and socioeconomic success, psychologist Tarmo Strenze surveyed a wide range of research papers dealing with the relationship between these two variables. His study yielded estimates of the correlation between IQ and income that ranged between 0.15 and 0.27. He reports:

The correlation of [IQ] with income is 0.20 considerably lower [than the correlation with job performance], perhaps even disappointingly low, being about the average of the previous meta-analytic estimates (0.15 by Bowles at al., 2001; and 0.27 by Ng et al., 2005).

That is, there is only a weak correlation between income and IQ. Many people of average intelligence become extremely wealthy and many brilliant people have modest income. In many businesses, intensity of purpose, tenacity and a strong work ethic are more important to success than high intelligence. Indeed, no matter what your level of intelligence, life is a do-it-yourself kit.