All people are introverts Some people are introverts No one is an introvert These are each true depending on the framing, and this aspect is even true to the

All people are introverts Some people are introverts No one is an introvert These are each true depending on the framing, and this aspect is even true to the original Jungian theory. Maybe that helps explain why quantification and studies can only go so far. Similar with learning styles... IMO holding any model lightly is a good idea. That way you don't need studies as badly when you have a conflicting result in which an introvert desperately wants to head to a party.