Abstract

Recent research reported that the entropy and determinism of pupillary diameter fluctuations differentiated children who solved an insight problem from those who did not, particularly during the final stages of problem solving. Although these findings are novel, children remain understudied in a field where most investigations have focused on adults. Given the scarcity of comparisons between these groups, the present study aimed to examine differences in performance and eye-tracking metrics in both children and adults who either solved or failed to solve an insight problem. The sample of children from the previous study was compared with a new sample of 80 adults who attempted to solve the 8-coin problem. The frequency of solutions, the proportion of fixations, and measures of pupillary fluctuations (entropy, determinism, and beta-scaling exponent) were compared across groups. Results showed that adults solved the problem more frequently than children. In addition, adults and solvers exhibited more focused and centralized fixation patterns across the problem setup, whereas children and non-solvers displayed broader and more disorganized observation patterns. Moreover, solvers were characterized by higher entropy than non-solvers in both children and adults during the final stages of problem solving. Determinism differentiated solvers from non-solvers only among children over time, but not among adults. Although adults' beta values were higher than those of children at certain windows, the beta-scaling exponent for both groups was described by brown noise. Previous findings suggest that the anticipatory dynamics of pupillary fluctuations during insight problem solving unfold similarly in both children and adults. Nevertheless, adults exhibit more predictable and structured variability in pupillary fluctuations, accompanied by constrained yet efficient observation patterns that result in higher performance. In contrast, children display more entropic and variable pupillary dynamics, accompanied by unconstrained yet less efficient observation patterns, leading to lower performance than that of adults.