Jean Piaget: 2 ideas worth knowing

2 ideas from Jean Piaget, each explained in a minute and credited to the original work. Free on Savvy.

Pour the same water into a taller glass, and a 5-year-old swears there's more
Jean Piaget showed young children two identical glasses of water, then poured one into a taller, thinner glass. Children under about seven typically insist the taller glass now hol…
— Jean Piaget, The Child's Conception of Number
Hide a toy under a blanket, and a young baby acts like it stopped existing
Jean Piaget found that infants younger than about eight months won't search for an object the moment it's hidden from view, as if out of sight truly means out of mind. The capacity…
— Jean Piaget, The Construction of Reality in the Child

Five ideas worth knowing, every week