  We examine an exactly solvable model of decoherence - a spin-system
interacting with a collection of environment spins. We show that in this model
(introduced some time ago to illustrate environment-induced superselection)
generic assumptions about the coupling strengths lead to a universal (Gaussian)
suppression of coherence between pointer states. We explore the regimes of
validity of these results and discuss their relation to the spectral features
of the environment and to the Loschmidt echo (or fidelity). Finally, we comment
on the observation of such time dependence in spin echo experiments.
