The only way of measuring meaningful intelligence (imo) is to look for indications of introspection. Attempts to understand that we are all prisoners of Plato's cave, and that actually it is impossible to live your life to the fullest, as we can't know everything that has ever happened and is happening. The fact is most people believe they are an above-average driver, and most people are religious because their family is religious, and most people vote for a politician because all their friends are voting for them. Cognitive biases are built into our biology as our brain prefers efficiency.
You can be the smartest in your class, or have a 150 IQ, or be the best lawyer, etc. But if you continuously fail to act in ways that demonstrates counter-intuitive thinking, then really are you even living your life? I do think the ability to overcome bodily impulses, which is something that is nurtured (for example, knowing that medicines you hated as a kid are good even though they taste funny so you take them anyway), is the clearest sign of intelligence. A person that maximizes counter-intuitive thinking would then be someone who is always skeptical and curious, both of their own and external thoughts, and that's something you can do anytime regardless of your IQ and experience.
Sorry for my bad english.