A collaboration with Prof. Oded Rechavi and Dr. Kenway Louie. Rational choice theory in economics assumes optimality indecision-making. One of the basic axioms of economic rationality is "Independence of Irrelevant Alternatives" (IIA), according to which a preference ratio between two options should be unaffected by introducing additional alternatives to the choice set. Violations of IIA have been demonstrated in both humans and in various animals and could therefore stem from common neuronal constraints. In order to examine this notion, we use the nematode Caenorhabditis elegans (C.elegans), an animal with only 302 neurons and a fully mapped connectome, to examine when and why economic rationality and violations of rationality occur. We developed tests for IIA violations by characterizing the choices that C. elegans make in olfactory chemotaxis assays. In each assay, we expose the worm to different odors that activate only specific neurons, thus involving in the choice process only defined neuronal networks, and test whether particular neuronal architectures are prone to producing irrational choices.