The adjective mental describes anything having to do with the mind, just as "physical" has to do with the body. Mental has to do with the intellect, the mind, or the brain.
There's a history of mental illness in that family, which is interesting because physically they're all so amazing. Makes you wonder why they did so well in one department but not the other. Some argue that standardized tests are no measure of your mental abilities. All they do is tell you how well you did on the test. That would be like testing your emotional depth based on how tightly you hug people. A person's mental gifts are difficult to measure.