Movin' and Groovin'
For the first six months of life, your baby has relied on you to set him in motion. You've carried him, rocked him, propped him up with pillows, and danced with him on your lap. Now he's driven to move and groove on his own.
Here's a typical scenario: Your 7-month-old is sitting up on her own and reaches across her body to grab at a toy. The act of reaching causes her to lose her balance. In an attempt to right herself, she twists her body and thrusts her hands out in front of her, landing on her tummy. Once on the floor, she may raise her head and gather her knees, as well as her hands, under her. She's on the runway in crawling position!
Set in Motion
Of course, "crawling" means different things to different babies. Another baby may, from a sitting position, discover that she can push her hands against the floor and scoot on her bottom to get from here to there. Regardless of her style, her first attempts may not lead to any forward movement -- she may try pushing her palms on the floor and find herself moving backward instead.
Indeed, it takes a while to get good at anything, and crawling is no exception. According to New York University psychologist Karen E. Adolph, PhD, who has conducted numerous studies on the topic, crawling speed increases by a staggering 720 percent over the first 20 weeks of learning, while the size of an infant's crawling "steps" increases by 265 percent. In other words, once she gets the hang of things, watch out: Crawlers can move!
Learning the Lay of the Land
Crawling doesn't merely boost physical skills. As your baby learns to move independently, she will become more aware of her surroundings and better able to navigate them, says Lise Eliot, PhD, author of What's Going on in There? How the Brain and Mind Develop in the First Five Years of Life (Bantam). There's a big difference between being carried around and getting somewhere yourself. Crawling helps kids learn to keep track of locations and use landmarks to orient themselves -- for example, she gets to her basket of toys by looping around the coffee table and heading toward the kitchen. "It's like the difference between driving the car and just riding along," says Eliot.
In addition, the very act of balancing in different positions takes place in the context of her own rapidly changing body. Her arms and legs might actually be longer from one month to the next, and she may weigh more. Further complicating the mix, as baby's skills become more advanced, her abilities change. In one of her studies, Adolph gathered a group of 9-month-olds who had been sitting up for a while but had only just started to crawl. In the first scenario, the babies were placed on a platform in view of a bright red ball 2 feet below. In their excited pursuit of the ball, the babies would have fallen off the platform if no one had caught them. Yet when they were seated with their legs dangling over the edge of the platform, the babies gazed at the tempting red ball but didn't reach for it because they knew they would fall.
Why were the babies more cautious in the second instance? The 9-month-old babies, with several months of sitting experience, knew what they could and couldn't do from that position. On the other hand, as novice crawlers they lacked both the depth perception and hand-eye coordination to judge their own abilities correctly during the precarious new activity.
In short, every new motor milestone involves learning how to balance and move in a different way, requiring constant fine-tuning of their bodies as they try new tasks.