A sufficiently intelligent person should be able, given enough training, to become proficient in any area of expertise.
Indeed! Combine several tests of mental potential into an omnibus test, and run a large group of people through the omnibus. If you run the results through common factor analysis, you will find that getting a good score on one subtest is highly correlated to getting a good score on each of the other subtests. Psychologists have named the common underlying cause g, the general intelligence factor. (Scaled for age and population variation, g becomes an IQ score.)
Indeed! Combine several tests of mental potential into an omnibus test, and run a large group of people through the omnibus. If you run the results through common factor analysis, you will find that getting a good score on one subtest is highly correlated to getting a good score on each of the other subtests. Psychologists have named the common underlying cause g, the general intelligence factor. (Scaled for age and population variation, g becomes an IQ score.)