Playing it safe: information constraints bias living systems towards less risky strategies*

To survive in complex, changing environments, biological organisms must employ an appropriately adapted strategy. For example, by making the right decisions, expressing the appropriate phenotype or implementing the most efficient foraging behaviour, etc. an organism can attain higher physical fitness in a given environment. However, in any realistic setting, an organism has only limited information about its environment, making it hard for it to `know’ the right strategy. We argue that strategies employed by organisms are fundamentally probabilistic, and define a probability of survival in terms of a distance measure between an organism's strategy and the statistics of the environment. Our measure for the probability of survival serves as a proxy for physical fitness. We then show that given constraints on an organism’s information gathering, the optimal strategy will have a natural bias towards lower risk, i.e., towards playing it safe. We quantify these considerations, and discuss how our prediction of inherent bias towards less risky strategies can be tested experimentally in biological systems.