Non-verbal behavior is very important in analyzing interpersonal communication. Think about waiving your arms when explaining something, nodding your head, or frowning.
In infancy you can observe an explosive growth. Many researchers focus on this age group. Think about studies aimed at learning more about speech behavior, maternal sensitivity, or learning behavior in infancy.
When a baby is born prematurely, this baby and his or her parents often experience a rough start. You can think about eating problems, high risk of infection, or even anemia.
In infancy you can observe an explosive growth. A lot of researchers focus on this age group and observe parent-infant dyads to get more insight in specific behaviors.