What goes into learning balance besides stronger muscles? The vestibular system. It consists of semicircular canals within the inner ear, plus a vestibule that houses important sense organs: tiny hairs called cilia, and minute bits of calcium carbonate called otoliths. Changes in your baby's head position cause the otoliths to tumble along the hair, which in turn provides the brain the information needed to make corrections in balance. Starting at around 7 months, the vestibular system becomes hyper-responsive, says Lise Eliot. It's the vestibular system that tells your beginning crawler how to adjust his trunk and legs so that his arms can pull him along more efficiently. Once he's upright, it tells him things like how far he can lean over before falling when he picks something up.
- Can drink from a cup
- Understands that an object might be behind something
- Makes multiple-syllable sounds
- May shy away from strangers
- Points at objects
- Rocks on all fours or crawls
In the Mouths of Babes
No matter how often you clean your floor, you'll still find yourself pulling small objects out of your baby's mouth. If there's a lost button on the floor, you can count on his finding it!
These explorations are a normal part of development. Babies begin to explore the world with their mouths even before birth; ultrasounds routinely show fetuses sucking their thumbs as early as 16 weeks. At birth, sensations in and around the mouth are the most highly developed, so once babies can reach for the world and take it in hand, they're eager to experience size, shape, texture, taste, and temperature by putting every object to the taste test. Mouthing peaks between 7 and 9 months and then declines steadily as babies become more adept at exploring the world with their hands. One study, by Jonathan Roberts and Martha Ann Bell at Virginia Polytechnic Institute and State University, in Blacksburg, noted that 8-month-old boys spend "an overall greater percentage of time mouthing" toys than girls of the same age. They attribute this to "faster brain maturation of female infants, who spend more time examining toys with their eyes."
While baby's in this stage, keep potential choking hazards away, and let him enjoy his hold on the world's delights and learn as he goes -- or chews.
Holly Robinson lives with her five children outside of Boston, Massachusetts.
Originally published in American Baby magazine, December 2005.
All content here, including advice from doctors and other health professionals, should be considered as opinion only. Always seek the direct advice of your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.