Physical Development

Between the third and fourth month, your baby's vision will improve. Seeing the world more clearly will trigger a host of other changes. Typically, he will:

• Notice objects that he was unable to perceive before, and work harder to reach them.
• Be able to maintain eye contact with you for at least a minute at a time.
• Gain depth perception and learn that objects are three-dimensional.
• Become interested in smaller objects, such as the patterns on fabrics or wallpaper (one enterprising mom picked up remnants of leftover wallpaper from a local decorator and hung a different one each day above her baby's crib).

Social Development

Although nights of uninterrupted sleep are still a few weeks away, your little one may be starting to develop a consistent routine. He may wake up at about the same time each morning, eat and stay awake for a short period, and then take a nap before lunch. In the afternoon, he may have a period of alert wakefulness followed by--you guessed it--a feeding and a nap, followed by another feeding and bed. He may even be able to sleep six hours at a stretch by this time.

Then again, many babies don't develop their own schedules at all. Try to organize as much of his day as you can, offering consistent times for bathing, outings, and bed. Don't worry if you need to vary the schedule sometimes--too much rigidity can be as stifling to children as it is to adults. But keep in mind that, as a general rule, your child finds predictability reassuring rather than boring.

Intellectual Development

You'll be happy to know that your baby's crying is on the decline. Infants cry an average of two hours a day in the second month, decreasing to one hour between the third and fourth months. The most common reasons for crying are to call for help (when he's hungry or uncomfortable), to shut out overpowering stimuli, and to release tension. Sometimes babies cry simply to get rid of excess energy so they can return to a more contented state.

Although you are the best judge of your baby's moods, infant cries are somewhat predictable in tone and pitch. For instance, a hungry cry tends to be short and low-pitched, rising and falling as it gains in intensity. An angry cry is more of a violent wail, while a long, high-pitched shriek followed by a pause may signal that your baby is in distress.

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.