Bolder stickleback fish make faster decisions, but they are not less accurate

There have been many investigations into consistent, individual differences in behavior (animal personalities), but rather less attention has been given to the possibility that individuals might differ consistently in their "cognitive style," which refers to the way information is acquired, processed, stored, or acted on. Both personality and cognition have important fitness consequences, and it has been proposed that variation in cognition could be functionally related to variation in personality. Here, we test this hypothesis using three-spined sticklebacks (Gasterosteus aculeatus) as a model and adopt a classic T-maze with food reward experimental paradigm. We first confirmed that fish choose the correct arm of the maze significantly more than would be expected by chance and that this improves with trial number. We then explored predictors of individual differences in the speed (time to making a decision) and accuracy (whether the first decision is correct) in decision making. We find bolder behavioral types (who tend to be male) arrive at the correct decision sooner than their shyer conspecifics. However, boldness was not related to decision accuracy. Moreover, we did not find any significant difference in fish’s improvement in decision accuracy over successive trials according to boldness or sex. This suggests that although bolder fish may acquire information more quickly because they make decisions faster, they do not differ from shyer conspecifics in their decision-making accuracy. The absence of such a trade-off might offer a functional explanation for why, in stickleback fish and many other species, bolder individuals tend to initiate movement and shyer individuals to follow—bold leaders may result in faster group decisions without compromising accuracy.