Binet (or WISC) jockey -- A psychometrician who primarily administers tests of general ability, AKA intelligence tests.
bra-size IQs -- Levels of general ability (intelligence) that are way below average; literally, IQ scores between 32 and 40, the typical range of bra sizes excluding cup size.
FLK -- This stands for 'funny-looking kid;' someone who has facial characteristics that suggest retardation.
LOBNH -- This is an acronym standing for "Lights On, But Nobody Home." Used by some medical personnel to refer to mentally challenged persons.
PITA syndrome -- This refers to a person consistently being a pain in the ass to other people. This term is occasionally used by psychologists to refer to a pattern of being consistently annoying or unpleasant.
room-temp IQs -- A slang term used by psychology majors to refer to those levels of cognitive ability that are borderline, but not quite low enough to be considered mentally retarded. Specifically, this refers to those in the 70-80 range.