With dancing, you could point out that the movement of your hips should be timed with the beat, and that the level of motion should be somewhere in a range that is neither too quiet nor too frenetic compared to the other dancers. You could throw in other rules as well, such as no finger-pointing, no white-boy overbite, no excessive repetitiveness, no monopolizing the entire dance floor, and so on. You might have dozens of rules when you are done, but the highly intelligent alien and the Asperger guy (probably an engineer) could learn them all fairly quickly. And from that point on, they could discern good dancing from poor dancing. They might even be able to imitate it, with some practice.