Standardized tests are a fundamentally flawed way of evaluating anything on a general level. Whether we are testing kids in schools, rats or chimps, we must always remember that standard tests are only as good as the questions we ask.
Intelligence and cognition are are NOT on a linear scale from stupid to genius. The continuum is multi-dimensional and we must acknowledge that as we evaluate the capabilities of all species including humans. Humans have evolved some unique capabilities in terms of communication and manual dexterity, but other species have their own capabilities that are neither better or worse, just different.
We have a couple of hens out in our yard, and it doesn't take much observation time to realize that they are a lot smarter than most people give them credit for. Similarly, just because a person may be autistic or dyslexic and they may have difficulty doing well on a test, but they may have capabilities that far exceed the average in certain areas. Not better or worse just different.
Standard tests are fine for evaluating the skills needed for a specific task, but they should never be the sole criteria for any decision.