What is the one single attribute that has consistently been found to correlate the most to a person's income?

Question

This is personally earned income not inherited.

Answer 1

Studies have shown that your income and wealth are directly related to the size and depth (together) of a person's vocabulary.

Answer 2

Diligence?

Answer 3

For males, their height in high school .... not in elementary school or as an adult. It is specifically, their adolescent height.

Probably IQ combined with EQ (emotional intelligence).

For women, obesity reduces income.

For males, being short in high school predicts a lower income.