I am aware that the linked text is not the newest anymore but due to some good explanations I still prefer it over most other sources available in the internet ... the current taxonomic assessment is still the same anyway ...
Concerning the self-rating of being more intelligent than average that's just typical human. Let me name another funny example: if you ask people about the coming soccer world champion, the majority (or at least a rather high percentage) will answer their own country will probably win, even if - obviously - the probability p = 1 that any team will win the tournament is distributed on all teams, so that even the best team has a rather low probability (not more than typically roughly p = 0.2 or lower) to become world champion.
I guess educated people are a bit atypical, in rating them selves on average less intelligent then they are. :D