That's exactly what I thought. In the context of Adams' mind experiment there's a problem with this approach: the aliens need to now both there is a goal to da

That's exactly what I thought. In the context of Adams' mind experiment there's a problem with this approach: the aliens need to now both there is a goal to dancing or conversing well, and what that goal is. (Which is confounded a bit by there being multiple goals for these activities, and not everybody's going for the same ones in any given context. Two people who just met will want a different thing from conversation than two friends shooting the shit.) However, Adams' rhetorical questions (though not, I think, his mind experiment itself) have a flaw: people with Asberger's syndrome generally know what the goal of those activities is (or at least, what they want out of it), but are unable to judge whether they're actually achieving those goals (since they have a hard time gauging other peoples reactions as you suggest). This fits with the mind experiment though. Suppose the aliens figure out that conversation and dancing have goals - even what those goals are. The alien still can't tell who the good conversationalists or dancers are without understanding things like human body language, vocal inflection, or subtle word choice - which is nearly the same set of problems people with Asberger's have.