Individual differences in laterality and personality are expected to covary, as emotions are processed differently by the two hemispheres and personality involves emotional behavior. Fish species are often used to investigate this topic due to the large variability in personality and laterality patterns. While some species show a positive relationship between lateralization strength and boldness, others show a negative relationship, and some show no relationship. To investigate whether this relationship follows changes in laterality and personality, we conducted a fully factorial design experiment manipulating predation and group size during early development. Results showed that the strength of laterality was influenced by predation threat, while social tendency and boldness were influenced by group size. These findings suggest that early life conditions can have an impact on laterality and social behavior. The relationship between laterality and personality traits, while present, was heavily influenced by the specific trial conditions, but not by the different developmental conditions.

This dataset was collected via video analysis. The analysis was conducted both manually by an operator, and via automated software. They are based on the movement of the individuals. The data have then been mostly used raw, and when transformed, it has been clearly stated.

The files are .xlsx and .docx. An R project with all the statistical analysis is included (.Rproj, .RData and .Rhistory).