Does bolder mean better? – Exploring the interaction between personality and social learning in the zebrafish (Danio rerio)

Abstract

Within shoals, how bold or shy a given fish is can have significant repercussions for both individual and group fitness. Boldness in fish has been correlated with exploratory behavior in novel environments, which may afford bolder individuals more opportunities to learn about resources relative to shyer conspecifics. Access to knowledge, in turn, predisposes individuals to becoming leaders within a group and allows them to play an influential role during consensus decision-making. In this study, we explored whether shy-boldness was a significant predictor of learning and leadership within small groups of zebrafish. Using a method previously developed within the Couzin lab, we were able to assign a unique shy-boldness (SB) score to each individual fish in our experiment. We then used a Y-maze setup to train fish in groups of 12 to associate a specific colored arm with the presence of a food reward, adjusting the size of the food reward across different groups (low, medium, high groups). At several intervals, fish were tested alone in order to assess how well learning had occurred in each individual. Following training, I conducted a correlation analysis between SB score and several measures pertaining to learning and leadership across all individuals. While significant results were found in the high food condition, these findings could be the result of Type-I error stemming from running multiple comparisons during the analysis. Overall, I concluded that shy-boldness was not a significant predictor of individual learning or leadership within our experiment. Future experiments could directly control for variance in SB scores within different food condition groups in order to further test whether any significant effects can be found.