sorority characteristics

If you read about AU sororities on this site, you see comments about what they tend to be characterized for...smart, wild, snobs, nerdy etc..

How in the world can any PNM differentiate during recruitment?

How can any PNM can tell that much about a house after 5-6 days? If they are really loving a house and then to find out later when they, go to that house that they are now a member of 'the wild' group, or the ---- whatever group?! I would think that most houses are are true mix of: smart girls, conservative girls, wild, snobs etc.