Your baby may spend a lot of time looking pensive, but she's not exactly a deep thinker. When she furrows her brow and purses her lips, she's more likely to be filling her pants than doing algebra. Still, she's starting to take some amazing mental leaps.
For the first time, she's beginning to understand the wonders of cause and effect. She'll start to realize that her crib shakes when she kicks it and her rattle makes noise when she shakes it. Even after making these discoveries, she'll want to test them again and again.
She's also learning to predict your actions. When she smacks her lips and reaches for mom's blouse, she knows that she'll soon be fed. She also knows that you're likely to pick her up if she flaps her arms in your direction. Before you even reach down to grab her, she'll probably smile in anticipation. When you pay attention to her and respond to her needs, you're doing more than making her feel safe and secure -- you're reinforcing her understanding of the world.
Even though your baby can't say any words, language is an important part of her life. She's now a better communicator, and she's learning how to use sound to connect with her caregiver. She can recognize her own name, too, so use it when speaking to her. Follow her cues to see what things are important to her. When she's looking at the family dog, say "dog" or "there's the dog." Name the toys that she grabs or the pictures that draw her attention.
Your baby is even ready to start joining in conversations. She'll make long vowel sounds like "oooo" and "eeee," especially when she's excited. She may also start experimenting with consonants. While she's "talking," her voice may rise and fall as if she were asking questions or making statements. Some babies start repeating the same consonant-vowel combination such as "bah" or "mah" over and over. This skill, called babbling, will become more noticeable in the next couple of months.
The best way to encourage her language development is to keep talking to her throughout the day. Repeat her sounds back to her and act as if you understand everything she says. When you talk to her, you can be sure she's listening. At her age, few things are more comforting -- or more educational -- than the sound of your voice.
Sears, William and Martha. The Baby Book: Everything You Need to Know About Your Baby From Birth to Age Two. 2003. Little, Brown and Co.
American Academy of Pediatrics. Caring for Your Baby and Young Child: Birth to Age Five. 2009. Bantam Books.
University of Florida, Department of Family, Youth, and Community Sciences. How I grow: Months three and four. August 2003. http://edis.ifas.ufl.edu/FY633
American Academy of Pediatrics, HealthyChildren.org. Cognitive Development: 4 to 7 months. http://www.healthychildren.org/English/ages-stages/baby/pages/Cognitive-Development-4-to-7-Months.aspx