Your baby will become more and more social this month, grinning, laughing, cooing and even initiating play. Her newfound fascination with rattles and other toys is more than just fun and games. She's practicing important cognitive and motor skills.

With her increased memory and attention span, sharper vision and stronger muscles, your four–month–old is learning behaviors today that are the stepping stones for crawling, walking and even talking. Embarrassed by your own urge to giggle, babble and coo? Don't be. Remember, her delighted response is good for her and for you.