[Drolefille]

After two degrees (either a BA/MA or a MA/PhD) you know the faculty, they know you and you're probably not being challenged the same way. You know the program very very well.

Some of it is just snobbery, but it's also realistic. State U. has one way of teaching their Psych. program and U of State teaches another way. To be well rounded and knowledgable in the field, you want multiple experiences.

It's not a REAL rule. It's a social thing. But some schools/professors will encourage you to look outward as well.