We replicate the Stanford marshmallow experiment with a sample of 141 preschoolers and find a correlation between lack of self-control and 2D:4D digit ratio. Children with low 2D:4D digit ratio are less likely to delay gratification. Low 2D:4D digit ratio may indicate high fetal testosterone. If...

We show that preschoolers exhibit the endowment effect as evidenced by experiments where children generally chose to keep their own toys rather than trading them for similar ones. Furthermore, we relate the emergence of this effect to children’s innate psychobiological traits—emotional...

A recent neurobiology study showed that monkeys systematically prefer risky targets in a visual gambling task. We set a similar experiment with preschool children to assess their attitudes toward risk and found the children, like the monkeys, to be risk seeking. This suggests that adult humans...