Development of a 4 Month Old Infant

Social Development

• The social development of a 4-month-old is exciting to behold. Slowing emerging from a sleeping/eating/crying newborn is a smiling, laughing and cooing baby who is capable of interaction beyond simply staring at a face or a toy. A 4-month-old girl will grab a baby rattle, bring her feet to her mouth and laugh during games of peek-a-boo.

  "Between four and seven months, your baby may undergo a dramatic change in personality ... Their unique character traits include their activity levels, their persistence, and their adaptability to the world around them---and these traits will become increasingly apparent during these months," according to the American Academy of Pediatric's website, HealthyChildren.org.

Physical Development

• Parents can usually relish balancing their baby's feet on their lap when their baby is 4 months old, as he learns to put his weight on his legs. Most babies at this age also learn to roll over, from front to back and from back to front. And many are not only holding toys but also reaching to get a stuffed bunny that is out of reach.

  The AAP says, "From age four to seven months, the most important changes take place within your child. This is the period when he'll learn to coordinate his emerging perceptive abilities (the use of senses like vision, touch, and hearing) and his increasing motor abilities to develop skills like grasping, rolling over, sitting up and possibly even crawling."

Eating Habits

• Finally, the day has come to break out the bibs, the small spoons and the highchair. Some pediatricians recommend starting a baby on solid foods by 4 months of age. Begin with rice cereal specifically made for infants. Follow the box's directions for a "baby's first feeding," which suggest mixing one part cereal with four or five parts water, formula or breast milk. Baby will most likely try eating the cereal off the spoon as she would nurse from a bottle. But that first messy feeding will make for great photos, as well as pave the road for pureed bananas and peas in a few months.

Sleeping Tendacies

• If it isn't joy enough for parents to see their 4-month-old eating and playing more, they will be blissful to learn 4 months is the age when most babies sleep longer at night. "Most" is stressed in that statement, and the babies who do sleep six- to eight-hour stretches at night will usually need some coaxing to do so.

  According to the non-profit Zero to Three organization's website, "The key is helping your baby learn how to get herself to sleep. Creating a soothing routine of lullabies, books and rocking before bedtime is very important. Then put your baby down in her crib while she's still awake. This gives her the chance to learn what it feels like to fall asleep on her own."

Ask a Doctor If ...

• No one can determine or suggest that a particular baby is not developing typically for his age without consulting a doctor. That's why the American Academy of Pediatrics says to check with a baby's pediatrician if the following signs are noticed:
  • At 4 months old, he cannot hold his head up when pulled into a sitting position.
  • He does not look around by turning his head to locate sounds by 4 months old.
  • At 5 months old, he doesn't roll over from front to back or back to front.
  • He doesn't smile at people's faces, his own reflection or at toys by 5 months old.