What role do early experiences play in later development? What elements of early environments are crucial for optimal development? What are the risks and protective factors that could explain children’s outcomes? Can children exposed to adversity in infancy develop positively? This article aims to address these questions by reviewing the most recent psychological theories and research.

Children undergo dramatic development during the first three years of life. The central accomplishments of early childhood include
•    physical growth and development,
•    development of the brain and nervous system,
•    sensorimotor and perceptual development,
•    information processing and language development, and
•    emotional development, which includes self-regulation, social understanding and attachment.

Children who are developing normally are characterized by functioning within normal ranges on measures of intelligence/cognition and achievement, using language effectively for communication, showing adequate relationships with others, and not having any continuing and debilitating emotional problems.

As has been postulated by a rich tradition of infant research, including seminal works of John Bowlby, Mary Ainsworth, Margaret Mahler and Donald Winnicott, healthy development depends not only on children’s biology and genetics, but also on the ability of their caregivers to provide nurturing, sensitive and responsive caregiving, environment that allows exploration and stimulation, and adequate diet and hygiene, safety, and health care. It is important to remember that all areas of development in early childhood are interrelated.

Development of a child is regulated by:
•    characteristics of the child, such as gene expression (e.g. temperament), prenatal and perinatal history, inherent or acquired physical or mental health conditions, etc.;
•    characteristics of the caregiver (sensitivity and responsiveness to affective cues, own physical and mental health, attachment state of mind, etc.),
•    and other aspects of the environment (socioeconomic status and resources, aspects of the neighborhood, natural disasters or armed conflicts).

The following examples stress the notion of interrelatedness, as well as highlight the active role both the child and the caregiver play in development of the child.
As discussed in the article on emotional development, infants and their caregivers interactively co-construct the environment needed for maturation of the areas brain responsible for emotional development. The infant’s ability to regulate emotions, then, coupled with stimulation provided by the caregiver to produce emotionally pleasant sensations. Because such stimulation arouses pleasant emotions, it encourages learning and, therefore, brain development.

 Another example of the interconnected feature of development is the impact that nutrition and feeding practices provided by caregivers have on numerous domains of the child’s development (e.g. motor activity, brain and intellectual development), manifestations of which in turn shape caregivers’ experiences in caring for the child.