  We have measured the 2-particle correlation function of atoms from a
Bose--Einstein condensate participating in a superradiance process, which
directly reflects the 2nd order coherence of the emitted light. We compare this
correlation function with that of atoms undergoing stimulated emission. Whereas
the stimulated process produces correlations resembling those of a coherent
state, we find that superradiance, even in the presence of strong gain, shows a
correlation function close to that of a thermal state, just as for ordinary
spontaneous emission.
