See, the reason I think it's completely different from astrology is that it's not going "LOL YOU'RE THIS RANDOMLY" and overly vague and generic. It's like saying you're left-brained or right-brained, it's an actual "Okay, are you an introvert or extrovert?"

Now, any description that is supposed to define a million people who just happen to share 4 characteristics is going to be a generalization, but it's not that much of a stretch to go "extroverts are more outgoing than introverts".