Final answer:
During the first year, infants experience rapid growth, with milestones at two months including holding their head steady, smiling, and cooing. At six months, they improve in vision, sitting, and start babbling. By one year, they begin to stand and may say first words.
Step-by-step explanation:
Infant Development Milestones
Infancy is a critical period of rapid growth and development that occurs after birth, seeing the child grow twice in length and triple in weight by the end of the first year. Within this period, infant development milestones occur at varying times, highlighting the unique pace at which each baby grows. At two months, an infant typically can hold their head erect and steady when upright, roll from side to back, and shows the beginnings of social interaction by cooing and smiling at parents.
Approaching six months, significant developmental changes include improved vision comparable to an adult's, depth and color perception, sitting up, beginning to crawl, transfer of objects from hand to hand, and the emergence of teeth. Babies at this age may also babble and start using two-syllable sounds like "mama" or "dada," and may show stranger anxiety.
By around ten to twelve months, infants are achieving milestones like standing with support, potentially taking their first steps, and may say a few words. They indicate understanding of simple commands, cooperate with dressing, and show interactive gestures like waving goodbye.