3.1 Physical Development in Infants and Toddlers

Significant physical developmental changes occur during the first two years of life. Growth charts help document developmental patterns and identify signs of abnormal growth.
Sleep is an essential biopsychosocial process, meaning it is influenced by biological, psychological, and social factors.
Infant sleeping arrangements and bedtime activities are deeply influenced by family and cultural factors. Some sleep methods are known to prevent sleep-related deaths.
Nutrition is an important component for the health and development of young children. With advances in physical development, the infant’s diet can begin to include solid food.
As the brain develops, once-automatic reflexes become controlled movements. The brain continues to specialize based on experiences and biological predispositions.
Malnutrition can both lead to significant health problems and limit growth and development.

3.2 Motor Development in Infants and Toddlers

Motor development progresses rapidly from infancy, starting with the ability to lift the head and advancing to jumping and climbing by two years of age.
Motor development milestones in the first year include rolling over, sitting up, crawling, standing, and eventually walking. Infants and toddlers also develop increasingly refined motor skills, such as grasping and manipulating objects.
Both gross and fine motor development are important for a child’s overall physical and cognitive development, and parents and caregivers can support the development of both types of skills through play and other activities.
Influences on motor development can include genetic predisposition, culture, and environmental factors such as opportunities for physical activity and play.

In the first two years of life, sensory abilities improve significantly.
During the first six months, the eye matures, and visual acuity and contrast sensitivity improve.
Psychologists have developed different methods for studying infant hearing, which show that infants have preferences for familiar sounds and can distinguish between familiar and unfamiliar voices.
Touch makes a critical contribution to our physical, cognitive, and social development.
Newborns can distinguish different tastes and odors, which can later influence children’s acceptance of new foods.
Intermodal perception is the perception of the world through multiple senses at the same time.

Piaget’s theory explains cognitive development in terms of stages, with changes happening through schema development. During the sensorimotor stage, infants go through six substages as senses, motor skills, and coordination develop.
Information processing theories examine infant attention, encoding, and memory, explaining development as a series of gradual changes in cognitive structures and processes.
Vygotsky describes cognitive development as occurring through social interactions and culture.
Multiple factors contribute to individual differences in cognitive development, including culture, social environment, socioeconomic status, and home environment.

Language and communication development follow a rapid progression in the first years of life.
Language development includes understanding the key features of language: phonemes, morphemes, semantics, syntax, and pragmatics.
Language milestones in the first two years include crying, cooing, babbling, gestures, holophrases, and telegraphic speech.
Three main types of theories explain the development of language: nativist, learning, and interaction theories.
Variations in language development occur through differences in exposure, quality of the environment and family interactions, and language exposure.