See How They Grow: An Infant's Physical Development

Home / Parenting / See How They Grow: An Infant's Physical Development


As stewards of God’s sons and daughters, parents have a sacred obligation to look after the needs of their children. Among these responsibilities is becoming aware of how an infant grows physically. With knowledge, parents can optimally nurture this process.

Just as infants’ brains develop at a phenomenal rate during the first year of life, their motor skills develop rapidly. They are learning constantly how to move their bodies and get their muscles to do new things. They frequently experience the exhilaration of achieving new physical tasks.

Generally, these skills develop in predictable ways. They develop cephalocaudally, meaning from head to tail. They also develop proximodistally--from the center of the body outward. They learn gross motor skills (large movements such as moving arms and legs) before they can learn fine motor skills (small movements such as grasping an object with the index finger and thumb).

All parents are naturally concerned about whether their baby is developing at a normal pace. Sometimes this concern leads to pushing an infant to do things he’s not ready for. It’s important to recognize that each infant is unique and will develop according to his own timetable. He has to take each new skill one step at a time.

The best way for a baby to prepare for a new physical accomplishment is to master the one he’s currently working on. Parents should be encouraging and excited about their infant’s new motor skills, but don’t be discouraged if his progress seems too slow for you. He’ll catch up, and he needs your support, not your anxiety, as you provide him with a nurturing environment. If you are concerned that there is something developmentally wrong with your infant, talk to your pediatrician.

Below are milestones of physical development you can expect during the first year of your baby’s life, along with suggestions to help you foster this development.

Month 1

Though your infant is very dependent on you, he comes equipped with reflexes to help him adjust to his new surroundings. He has almost fully developed senses of taste and smell. His eyes cannot yet fully focus at close range. He can see objects best when they are 30 to 40 inches away from his face. He will try to lift up his head and look around. He quickly learns to pick out his mother’s voice from other female voices. By the end of the first month he can hear differences in similar sounds.

During this first month, you should:

  • Support his body and head when you hold him.
  • Understand that he is totally dependent on you to take care of his body.
  • If he looks uncomfortable, change his position for him.
  • Remember that he is still adjusting to the new physical world around him.

Month 2

Your baby will start to learn how to lift himself by his arms, roll from his side to his back, and hold his head steady when you hold him upright. He can focus his eyes and see colors nearly as well as adults. Physical play is increasingly important to developing his motor abilities.

During this second month, you should:

  • Start using his new motor skills in your play with him. Lay him on his back on your lap, take his hands in yours, and move them to play peek-a-boo. Hold on to his feet and rotate them as you sing songs like “The Wheels on the Bus.”
  • Make sure he can see your face as you talk and play with him.

Month 3

Your baby has stronger neck muscles, helping her lift up her head and shoulders. Though she is stronger, continue helping her support her body and head. She has better control over her leg and arm movements, though they may still be jerky. She develops a visual preference for human faces. She begins to reach for things.

Month 4

She begins learning how to roll from her back to her side. She can sit up with your support on her lower ribs. She tenses herself for you to lift her. She can hold her hand steady and is beginning to move her hands to her mouth more. She probably will start putting things in her mouth more often, which is her way of exploring things. This helps her learn.

During this fourth month, you should:

  • Be sure to keep out of reach harmful things that shouldn’t go in your baby’s mouth.
  • Keep her hands clean.
  • Give her plenty of opportunities to use her new skills, such as letting her sit up on your lap with your help.
  • Continue playing games that involve her body and require some movement. She will get better at them and you will be able to play games that require more motor control.

Month 5

Your infant is gaining better control over his thumb and will start using it more. He will begin to reach and grasp things that are moving. He’s almost able to sit up on his own, allowing him to move both his hands around freely and interact with things while sitting up. He begins fingering things while he is sitting.

During this fifth month, you should:

  • Support his body as he tries to sit up on his own.
  • Keep harmful things out of reach.
  • Give him chances to reach for things himself. Don’t place everything into his hands.
  • Put things within his reach and allow him to have room to move around.
  • Sit him on a blanket on the floor with toys around him that he can reach for himself and hold in his hands and mouth.

Month 6

Your infant may be able to sit without support. His vision is almost as good as yours. He can reach for and grab almost anything. He will continue to explore things by fingering them and putting them in his mouth.

Month 7

Your infant can sit up by himself. He is beginning to show pre-walking movements, such as crawling and making stepping motions when you hold him underneath his arms. He can reach for things with only one arm rather than needing both arms.

During this seventh month, you should:

  • Give him plenty of opportunities to use his new skills.
  • Hold him in positions that allow him to move his feet.
  • Allow him safe areas where he can crawl around.
  • Avoid baby walkers as a way to encourage movement because they block a baby’s view of his legs. A baby’s ability to see his own movements is important to motor skill development. Walkers may delay walking.
  • Instead of a walker, put him in a Johnny Jump-up.

Months 8 and 9

During the eighth month your infant learns how to pull herself up to a standing position. She can support herself with one hand while standing. She also develops the ability to perceive emotional expressions. Use emotions in your play with her, such as showing excitement when she begins learning how to stand on her own. During the ninth month your infant can begin to play pat-a-cake on her own.

Months 10 to 12

She will start standing with support by holding onto nearby furniture or onto your hands or legs. She’ll make stepping movements as she holds onto furniture. She’ll be able to walk while holding onto furniture or with the support of your arms. Within a few months of her first birthday (before or after), she’ll be able to walk on her own.

During these months, you should:

  • Help her stand and encourage her to stand as much as she can on her own.
  • Don’t hold her all the time. Give her chances to use the skills she’s working on.
  • Put her on the floor so she can work on getting up herself.

Written by Kathryn Vaughn, Research Assistant, and edited by Chris Porter and Stephen F. Duncan, professors in the School of Family Life, Brigham Young University.


  1. Berger, K. S., & Thompson, R. A. (1995). The developing person: Through childhood and adolescence. New York: Worth Publishers.
  2. Berk, L. A. (2001). Development through the lifespan (2nd ed.). Needham Heights, MA: Allyn and Bacon.
  3. Bowlby, J. (1952). Maternal care and mental health. (2nd ed.). Geneva, Switzerland: World Health Organization.
  4. Cooper, R., Abraham, J., Berman, S., & Staska, M. (1997). The development of infant's preference for motherese. Infant Behavior and Development, 20(4), 477-488.
  5. Finchman, D. (1998). Child development and marital relations. Child Development, 69(2), 543-574.
  6. Grych, J., & Clark, R. (1999). Maternal employment and development of the father-infant relationship in the first year. Developmental Psychology, 35(4), 893-903.
  7. Hayne, H., & Rovee-Collier, C. (1995). The organization of reactivated memory in infancy. Child Development, 66, 893-906.
  8. Heinicke, C., & Guthrie, D. (1992). Stability and change in husband-wife adaptation and the development of the positive parent-child relationship. Infant Behavior and Development, 15(1), 109-127.
  9. Houston, D. M., Jusczyk, P. W., Kuijpers, C., Coolen, R., & Cutler, A., (2000). Cross language word segmentation by 9-month-olds. Psychonomic Bulletin & Review, 7(3), 504-509.
  10. Johnson, M. (2000). Functional brain development in infants: Elements of an interactive specialization framework. Child Development, 71(1), 75-81.
  11. Lamb, M., & Bornstein, M. (1987). Development in infancy. New York: Random House Inc.
  12. Lew, A., & Butterworth., G. (1997). The development of hand-mouth coordination in 2- to 5-month-old infants: Similarities with receiving and grasping. Infant Behavior and Development, 20(1), 59-69.
  13. Merriman, J., Rovee-Collier, C., & Wilk, A. (1997). Exemplar spacing and infants' memory for category information. Infant Behavior and Development, 20(2), 219-232.
  14. Rochat, P., & Goubet, N. (1995). Development of sitting and reaching in 5- to 6-month-old infants.Infant Behavior and Development, 18(1), 53-68.
  15. Shore, R. (1997). Rethinking the brain: New insights into early development. New York: Families and Work Institute.
  16. Snow, C. (1989). Infant development. New Jersey: Prentice Hall.
  17. Siegel, A., & Burton, R. (1999). Effects of baby walkers on motor and mental development in human infants. Developmental and Behavioral Pediatrics, 20(5), 355-361.
  18. Van Der Meer, A. (1994). Great beginnings: An illustrated guide to you and your baby's first year.New York: Dell Publishing.
  19. Ward, M., Lee, S., & Lipper, E. (2000). Failure to thrive is associated with disorganized infant-mother attachment and unresolved maternal attachment. Infant Mental Health Journal, 21(6), 428-442.
  20. Waters, E., Weinfield, N., & Hamilton, C. (2000). The stability of attachment from infancy to adolescence end early adulthood: General discussion. Child Development, 71(3), 703-706.
  21. Zeanah, C. (Ed.). (2000). Handbook of infant mental health. (2nd ed.). New York: The Guilford Press.
  22. Zeanah, C., Boris, N., Heller, S., Hinshaw-Fuselier, S., Rovaris, M., & Valliere, J. (1997). Relationship assessment in infant mental health. Infant Mental Health Journal, 18(2), 182-197.