No, there is no single universal neutral standard of cognition. Memory tasks are different from mental rotation tasks, which are different from emotion-reading

No, there is no single universal neutral standard of cognition. Memory tasks are different from mental rotation tasks, which are different from emotion-reading tasks, etc. But, it turns out that performance at a huge variety of sub-tasks is highly correlated. E.g. reaction time (catch a falling ruler as fast as you can) correlates with ability to solve math problems, which correlates with ability to control impulses. This is why IQ, as a general measure that covers a wide variety of tasks, is so useful. (Of course, that's not to say IQ covers everything about cognition in some absolute way; it doesn't measure ability to balance on a beam, for example, AFAIK).