From birth, infants express needs that demand immediate gratification, most notably for milk, sleep, or a cuddle. But it's often not until that first smile, when they're between 1 and 2 months old, that we realize they want social interaction as well. Their smiles say to us that they are happy, content, and enjoying what's going on around them. Around 4 or 5 months, smiling takes on an auditory dimension and turns into laughter.
An environment that supports and recognizes the lightness of life is essential for cultivating a child's sense of fun. Respond to your child's attempts at levity and be willing to do silly things over and over.
Here's what tickles your baby's funny bone and why -- from infancy to toddlerhood.