We investigate the consistency of prosocial behaviors in response to changes in the institutional setting of a lab-in-the-field experiment involving primary school students in El Salvador. Students play variants of the dictator game allowing the option to take and with relative unequal initial endowments. We exploit within-subject variation and find that children are sensitive to the widening of the choice-set, with a significant drop in the contributions when the take option becomes available. Higher cognitive skills are systematically associated with higher levels of prosociality and lower sensitivity to changes in the choice set. Irrespective of the initial inequality in the endowment and their cognitive skills levels, children converge to a similar split of the final payoff. This is consistent with inequality aversion. The relationship between individual traits in childhood and the degree of consistency of prosocial behaviors appears to vary depending on the type of institutional change in the dictator game.