  Hyperfine interactions in the light meson and baryon sectors are generalized
to the charm and bottom systems. It is pointed out that an attempt to increase
the value of the wave function at the origin to account for the unusual ratio
of $\Lambda_{b}$ to the $B^0$ lifetimes could spoil the good agreement among
the baryon and meson hyperfine mass-splitting. Including spin effects and
taking phase space differences into account we predict that the decay rate of
the $\Lambda_{b}$ can be increased relative to that of the $B^0$ meson by about
7%.
