The physics of kinetic effects on the resistive wall mode (RWM) stability is studied, and a comparison between reversed field pinch (RFP) and Tokamak configurations is made. The toroidal, magnetohydrodynamic (MHD)-kinetic hybrid stability code MARS-K, in which the drift kinetic effects are self-consistently incorporated into the MHD formulation, is upgraded with an extensive energy analysis module. In the tokamak configuration, the kinetic effect can stabilize the mode with very slow, or vanishing plasma rotation, due to the mode resonance with the toroidal precession drift of thermal trapped particles. In RFP, instead, stabilization of the RWM comes mainly from the ion acoustic Landau damping (i.e., the transit resonance of passing particles). In the high beta region, the critical flow rotation frequency required for the mode stabilization is predicted to be in the ion acoustic range. Detailed physical analyses, based on the perturbed potential energy components, have been performed to gain understanding of the stabilizing mechanism in the two different systems.