  Social networks can sustain cooperation by amplifying the consequences of a
single defection through a cascade of relationship losses. Building on Jackson
et al. (2012), we introduce a novel robustness notion to characterize low
cognitive complexity (LCC) networks - a subset of equilibrium networks that
imposes a minimal cognitive burden to calculate and comprehend the consequences
of defection. We test our theory in a laboratory experiment and find that
cooperation is higher in equilibrium than in non-equilibrium networks. Within
equilibrium networks, LCC networks exhibit higher levels of cooperation than
non-LCC networks. Learning is essential for the emergence of equilibrium play.
