Out of curiosity, how are you defining the two? I ask because a lot of people tend to define them at "enjoys interactions with (larger numbers of) people" vs "does not enjoy interactions with (larger numbers of) people". The definition I like is that an extrovert gains (emotional) energy from interacting with people, while for an introvert those same interactions are draining. Both can enjoy the interactions, it's just a matter of how long they can sustain it.