Personality expression is shaped by the early experienced social context in predatory mites.

Research Highlights: Schausberger, P., & Nguyen, T. H. (2024). Early social isolation disrupts adult personality expression in group-living mites. Journal of Animal Ecology. https://doi.org/10.1111/1365-2656.14169. Personality traits in animals have been of great interest in the last decades. The number of studies demonstrating the existence of personality in a wide range of taxa is growing rapidly. Although the effect of early experience on later average values of behavioural traits is well documented, very few articles demonstrate the effects of those factors on personality expression itself. One factor in particular received very little, if not no, attention: social isolation. Although social isolation is known to have major impacts on later animal behaviour, it is still unknown whether it may favour or inhibit personality expression. In a recent study, Schausberger and Nguyen (2024) demonstrated that early-life social isolation had strong effects on adults of the predatory mite Phytoseiulus persimilis. They show for the first time that early social isolation decreased the expression of personality in the activity of adults when tested in a social context. Interestingly, they observed the opposite effect when the same mites were tested alone: previously isolated mites were highly repeatable but group-reared mites were not. Finally, they also show an indirect effect of early social isolation through mating: mating with a male who experienced social isolation increased the behavioural repeatability of females. This study not only reinforces the established understanding of personality but also paves the way for future research in the field.