  The effect of interactions near the coincidence of two Landau levels with
opposite spins at filling factor 1/2 is investigated. By mapping to Composite
Fermions it is shown that the fluctuations of the gauge field induces an
effective attractive Fermion interaction. This can lead to a spin-singlet
ground state that is separated from the excited states by a gap. The magnitude
of the gap is evaluated. The results are consistent with the recently observed
half-polarized states in the FQHE at a fixed filling factor. It is suggested
that similar anomalies exist for other spin configurations in degenerate
spin-up and spin-down Landau levels. An experiment for testing the spin-singlet
state is proposed.
