  We calculate the distribution of interparticle normal forces $P(F)$ near the
glass and jamming transitions in model supercooled liquids and foams,
respectively. $P(F)$ develops a peak that appears near the glass or jamming
transitions, whose height increases with decreasing temperature, decreasing
shear stress and increasing packing density. A similar shape of $P(F)$ was
observed in experiments on static granular packings. We propose that the
appearance of this peak signals the development of a yield stress. The
sensitivity of the peak to temperature, shear stress and density lends credence
to the recently proposed generalized jamming phase diagram.
