Efficient visual information sampling develops late in childhood

It is often unclear which course of action gives the best outcome. We can reduce this uncertainty by gathering more information, but gathering information always comes at a cost. For example, a sports player waiting too long to judge a ball's trajectory will run out of time to intercept it. Efficient samplers must therefore optimize a trade-off: when the costs of collecting further information exceed the expected benefits, they should stop sampling and start acting. In visually guided tasks, adults can make these trade-offs efficiently, correctly balancing any reductions in visuomotor uncertainty against cost factors associated with increased sampling. To investigate how this ability develops during childhood, we tested 6- to 11-year-olds, adolescents, and adults on a visual localization task in which the costs and benefits of sampling were formalized in a quantitative framework. This allowed us to compare participants to each other and to an ideal observer who maximizes expected reward. Visual sampling became substantially more efficient between 6 and 11 years, converging onto adult performance in adolescence. Younger children systematically undersampled information relative to the ideal observer and varied their sampling strategy more. Further analyses suggested that young children used a suboptimal decision rule that insufficiently accounted for the chance of task failure, in line with a late developing ability to compute with probabilities and costs. We therefore propose that late development of efficient information sampling, a crucial element of real-world decision-making under risk, may form an important component of suboptimality in child perception, action, and decision-making.