  Information is increasingly being viewed as a resource used by organisms to
increase their fitness. Indeed, it has been formally shown that there is a
sensible way to assign a reproductive value to information and it is
non-negative. However, all of this work assumed that information collection is
cost-free. Here, we account for such a cost and provide conditions for when the
reproductive value of information will be negative. In these instances,
counter-intuitively, it is in the interest of the organism to remain ignorant.
We link our results to empirical studies where Bayesian behaviour appears to
break down in complex environments and provide an alternative explanation of
lowered arousal thresholds in the evolution of sleep.
