In shaping how individuals explore their environment and interact with others, personality may mediate both individual and social learning. Yet increasing evidence indicates that personality expression is contingent on social context, suggesting that group personality composition may be key in determining how individuals learn about their environment. Here, we used recovery latency following simulated predator attacks to identify Trinidadian guppies (Poecilia reticulata) that acted in a consistently bold or shy manner. We then employed network-based diffusion analysis to track the spread of a novel foraging behaviour through groups containing different proportions of bold and shy fish. Informed associates promoted learning to a greater extent in bold individuals, but only within groups composed predominately of bold fish. As the proportion of shy fish within groups increased, bold individuals instead emerged as especially effective demonstrators that facilitated learning in others. Individuals were also more likely to learn overall within shy-dominated groups than in bold-dominated ones. We demonstrate that how individuals learn is conditional on group personality composition, indicating that selection may favour traits enabling individuals to better match their behavioural phenotype to their social environment.

Lab-reared Trinidadian guppies (Poecilia reticulata) were repeatedly exposed to a simulated predation event to evaluate their risk-taking tendencies.

Individuals that were quick to resume normal movement following these "attacks" were labeled as bold, while individuals slow to resume movement were labelled as shy.

We then formed groups containing different proportions of bold and shy individuals:
-Bold-dominated groups: 8 bold fish, 2 shy fish
-Mixed groups: 5 bold fish, 5 shy fish
-Shy-dominated groups: 2 bold fish, 8 shy fish

Twelve groups of each composition were formed.

On the day following group formation, nearest-neighbour shoaling associations were recorded during focal follows to construct a proximity-based social network for each group. Measurements of individuals' elective group size were also made during these shoaling observations.

We then presented groups with a novel foraging task consisting of an opaque cylinder with a small entrance hole in the lower half and food items floating on the water's surface within.

Groups were given 20 min to interact with device. During this time, we recorded each individual's latency to solve the task (i.e. entering the cylinder).

For those individuals that entered the device, we further recorded how many times they did so and whether feeding strikes were observed.

Please see the ReadMe file for information on using this dataset. We have additionally included R code to reproduce the analyses reported in the main text and supplementary material.