Dizygotic twins share more genetic material than any other sibling pair, but less than monozygotic twins

Piaget believed that ____ in toddlerhood is the basis of categorization

a. object permanence b. deferred imitation c. mental representation d. hindsight bias

Which of the following increases the risk of having a child with Down syndrome?

a. smoking while pregnant b. alcohol consumption c. maternal age d. paternal stress