  Differential diffusion is a source of instability in population dynamics
systems when species diffuse with different rates. Predator-prey systems show
this instability only under certain specific conditions, usually requiring
Holling-type functionals involved. Here we study the effects of intraspecific
cooperation and competition on diffusion-driven instability in a predator-prey
system with a different structure. We conduct the analysis on a generalized
population dynamics that bounds intraspecific and interspecific interactions
with Verhulst-type saturation terms instead of Holling-type functionals. We
find that instability occurs due to the intraspecific saturation or
intraspecific interactions, both cooperative and competitive. We present
numerical simulations and show spatial patterns due to diffusion.
