>>13437700IQ is an objective measure of general intelligence, a variable that heavily correlates with any form of intelligence you would define and with the ability to perform tasks (quickly) that you would agree require intelligence. It is a relatively stable variable from about the age of 4, meaning it doesn’t change much over one’s lifespan. You can gain some points with mental and physical exercise, education and learning languages, some mental illnesses like depressions affect it negatively and it (fluid intelligence) slowly decays with age starting at about age 25. Again, mental and physical exercise and languages serve very well in conserving / slowing the decay.
It is a very good predictor of socioeconomic success, but that can be compensated with work, so low IQ doesn’t totally inhibit anyone’s chances, as long as it isn’t too low. Besides, low IQ doesn’t generally coincide with enjoyment of cognitive tasks, so if you want to do STEM, you are most likely already above average.
