  The long-time behavior of certain fast-decaying infinite temperature
correlation functions on one-, two- and three-dimensional lattices of classical
spins with various kinds of nearest-neighbor interactions is studied
numerically, and evidence is presented that the functional form of this
behavior is either simple exponential or exponential multiplied by cosine. Due
to the fast characteristic timescale of the long-time decay, such a
universality cannot be explained on the basis of conventional Markovian
assumptions. It is suggested that this behavior is related to the chaotic
properties of the spin dynamics.
