danmeth:

THE CHEERS INTELLIGENCE GRAPH
#18 In A Series Of Pop-Cultural Charts
 
For just an average bar, the patrons and staff of Cheers really run the gamut of IQ levels. 

*Though one could argue that being an accountant takes more brains than being a barmaid, I put Carla above Norm because all that beer definitely has long-term effects on the cerebrum.