Very recently I've seen a chav wearing glasses and I was very surprised at the fact that I've found it difficult to instantly class him as scum. The two stereotypes clashed and the "educated folks wear glasses" one was winning for a second.
Either way, check out this fun little picture I've found on vk.com. It demonstrates the effect quite nicely.
|From left to right: truck driver - professor, slut - "hip chick", skinhead - stylist, slob - artist.|