  We derive a universal form for the correlation function of general n
component systems in the limit of high temperatures or weak coupling. This
enables the extraction of effective microscopic interactions from measured high
temperature correlation functions. We find that in systems with long range
interactions, there exist diverging correlation lengths with amplitudes that
tend to zero in the high temperature limit. For general systems with disparate
long range interactions, we introduce the notion of generalized Debye length
(and time) scales and further relate it to the divergence of the largest
correlation length in the high temperature (or weak coupling) limit.
