Physical Development

One of the most appealing parts of the house, from a baby's perspective, is the staircase. He sees it as a gigantic jungle gym, and he's intrigued by the way family members go up and down. Unfortunately, he doesn't yet have the skills to imitate them. But that won't keep him from trying.

To prevent accidents, install sturdy, wall-mounted gates at the top and bottom of each staircase. (Don't use accordion-style gates, which can strangle children if their heads get caught in the openings.) Let baby practice climbing up the first couple of stairs under close supervision--climbing down, facing backwards and with feet first, shouldn't be attempted until he's at least a year old. Stairs should be carpeted, and it's a good idea to carpet the area at the foot of the staircase, as well. You can also place an exercise mat at the foot of the stairs to cushion the inevitable falls.

Social Development

As soon as your baby grasps the concept of "no," he will start playing with it as if it's an interesting new toy. To elicit a "no" (and the attention that comes with it), he'll bang on tables and chairs, pull at your clothes, or head for objects that you've placed off-limits, such as the computer or phone cord. If you don't say "no" fast enough, he'll slow his pace, give you a big smile, and continue on his way. The point of this game isn't to reach the forbidden item--it's to interact with you. And the best way to handle it isn't punishment, but providing safe, alternative ways to play together.

Intellectual Development

Baby's understanding of "no" will soon extend to using it himself, either in words or through a definitive shake of the head. Although he's probably not yet sure what it means, it feels natural to him to move his head from side to side rather than up and down--which means that it will take him longer to grasp the concept of "yes." Once he understands about "no," he'll practice refusing everything from baths to diapers to his favorite meals. It's quite a challenge to get food into the mouth of a child who is frantically shaking his head back and forth, but millions of parents have mastered it--and you will, too.

Note: The information above offers general guidelines, but all babies develop differently, and few hit their milestones precisely when the conventional wisdom says they should. If your child was born prematurely, you may want to use your due date as a baseline for following baby's development.