Related abilities
Is interested in interacting with others, e.g. peek-a-boo (9-12 months)
Is able to sit unsupported and turn head to look at objects without losing balance
Enjoys and seeks out various ways to move and play (9-12 months)
Is generally happy when not hungry or tired (9-12 months)
Is able to enjoy a wide variety of touch, noise, and smells (9-12 months)