The Year Ahead: Age 4

"Physical development consists of both gross motor (GM) and fine motor (FM) development," says Cheryl Wu, M.D., of LaGuardia Place Pediatrics in New York City. "While every child develops at their own pace, there are certain milestones I expect most of my patients (90 to 95 percent) to achieve by their fourth birthday." By four years of age, a child can balance for at least three seconds on one foot, walk on a "tightrope," and hop on one foot. A 4-year-old can also copy a cross, draw a square, and draw something that looks like a person. She can definitely zip up her coat and work buttons.

"If your 4-year-old cannot walk up stairs without assistance, or run, that warrants a discussion with your pediatrician," says Brenda Rogers, M.D., a pediatrician at Children's Mercy Hospitals and Clinics in Kansas City, Missouri. "We sometimes see children who are a bit behind in physical development, but way ahead in language, fine motor, and social skill development." According to Anatoly Belilovsky, M.D., a Brooklyn-based pediatrician, lack of development isn't always because of delay. "It could be a lack of motivation on the child's part. Take a look at his surroundings: Does he have too many toys? Does he not spend enough time with other kids? Is he inside most of the time and does he need space to run around outside? Reaching these milestones isn't just about ability -- it's ability coupled with motivation."