An infant begins smiling and waving when seeing it's mom. What stage of piaget's theory of cognitive development does it reflect

Which characteristic do healthy families have in common? a. having above average household income b. ignoring one another’s happiness c. demonstrating love for oneself d. communicating with one another

Which list describe the aspects of health that should be in balance to archieve total wellness

If human development really does proceed continuously, what value does stage theories of development have?