The “‘sunk cost fallacy,’ as economists call it, is one of many ways that humans allow emotions to affect their choices, sometimes to their own detriment. But the tendency to factor past investments into decision-making is apparently not limited to Homo sapiens.” From the The NYT: Mice Don’t Know When to Let It Go, Either. (Congratulations, everyone. Our decision-making skills have reached the level of a rodent with a tiny head.)