  We find that the temperature dependence of the drag resistivity ($\rho_{D}$)
between two dilute two-dimensional hole systems exhibits an unusual dependence
upon spin polarization. Near the apparent metal-insulator transition, the
temperature dependence of the drag, given by $T^{\alpha}$, weakens with the
application of a parallel magnetic field ($B_{||}$), with $\alpha$ saturating
at half its zero field value for $B_{||} > B^{*}$, where $B^{*}$ is the
polarization field. Furthermore, we find that $\alpha$ is roughly 2 at the
parallel field induced metal-insulator transition, and that the temperature
dependence of $\rho_{D}/T^{2}$ at different $B_{||}$ looks strikingly similar
to that found in the single layer resistivity. In contrast, at higher
densities, far from the zero field transition, the temperature dependence of
the drag is roughly independent of spin polarization, with $\alpha$ remaining
close to 2, as expected from a simple Fermi liquid picture.
