Infancy & Early Childhood Development

Child development begins even before birth. A healthy pregnancy and a positive early childhood environment are crucial to normal infant physical and mental growth 2. According to the World Health Organization, some of the most detrimental factors to early childhood development include malnutrition and dietary deficiencies, a lack of learning opportunities and exposure to violence.

Types of Development

There are multiple areas of growth and development that occur throughout infancy and early childhood. Cognitive development refers to brain development and the capacity for learning 1. Psychosocial and emotional development are terms that refer to a person's social and emotional growth. Physical development encompasses bodily growth and the refinement of motor skills. Linguistic development is the acquisition of speech and language.

Role of Brain Development

Brain cells develop in utero, but the connections that allow a child to utilize knowledge do not occur until after birth 1. These synaptic connections are the result of everything a baby experiences and are greatly influenced by environment. The brain continues to develop these connections throughout life 1. Until about age 8, there is a superabundance of these connections, many of which are not useful. Gradually, the brain eliminates unused connections, leaving room for the connections used most frequently. These synapses control every aspect of life, including motor function, emotion, social interaction, speech and learning.

Time Frame

A baby’s physical growth occurs fastest during the first year. The average baby doubles his birth rate by age six months and triples it by one year. Motor skills develop rapidly starting at about 18 months, when most children learn to walk unaided. Cognitive and linguistic development accelerates around age 2. According to the Clearinghouse on Early Education and Parenting, the period from ages 2 to 6 years is the most important time for language acquisition.


Two main theories have shaped the study of early childhood development. Developmental psychologist Jean Piaget theorized that children progress through four stages of cognitive development from birth to adolescence. His theory helps explain why children process new information differently than adults. Psychoanalyst Erik Erikson developed a theory of psychological and emotional development throughout a person’s life. He stated that people progress through eight stages beginning at birth, each characterized by a basic psychosocial conflict.


Though some aspects of growth are intrinsic, a child’s environment plays a critical role in all areas of development. As the World Health Organization states, “Early experiences determine health, education and economic participation for the rest of life.” Parents and caregivers can create a stimulating environment for infants and toddlers to increase cognitive functioning. Speaking and reading to children improves language and literacy acquisition. Interactive toys and activities promote physical health and improve motor skills. Learning opportunities occur every day in a child’s environment.