Theories of Developmental Psychology

Developmental Psychology aims not only to identify the changes that occur throughout a lifetime but also to predict, explain, and control what influences those changes. Ultimately, the goal is to determine the factors that affect normal development to figure out the best interventions when development is abnormal.

One of the biggest debates in the field of developmental psychology is nature versus nurture. Nature is basically genetics. It's the uncontrollable factors that affect our actions. Nurture is external factors such as life experiences, exposure, and learning, which influence development. The debate centers around how much influence each has on development.

Freud's theory of psychosexual development centers on the idea that life is built around pleasure and tension. He believed that the first five years are critical and that conflict plays a big role during psychological development. Each stage centers around a specific conflict. Moving onto the next stage relies on the resolution of the current stage.

Freud's first milestone is the oral stage, which covers birth to one year. Pleasure centers on the mouth, which Freud believes explains why infants fixate on sucking and biting. The anal stage occurs during ages one to three and connects to potty training and parents telling toddlers where they can and cannot have a bowel movement. Next is the phallic stage, from ages three to six, when the child realizes there are anatomical differences between men and women and learns to identify with the parent of the same gender. Latency is next, from age six through puberty, where the libido is dormant while other learning takes place. Finally, the genital stage begins at puberty and continues into adulthood.

Erik Erikson developed another theory that focuses on stages and the resolution of crisis. Erikson's theory goes from childhood through the entire life. It includes eight stages, each tied to a basic social institution. Erikson's theory draws from Freud's psychosexual stages but also incorporates his experiences as a teacher and psychoanalyst.

Erikson's eight stages are as follows:

• trust versus mistrust in infancy
• autonomy versus shame in early childhood
• initiative versus guilt as a toddler
• industry versus inferiority in primary school
• identity versus role diffusion in adolescence
• intimacy versus isolation in young adulthood
• generativity versus stagnation in adulthood
• integrity versus despair in old age

Jean Piaget had his own theory of cognitive development. He believed that intelligence is not a fixed trait but a process affected by maturation and the external environment. Piaget's theory aims to explain how infants and children learn to think and reason, building an understanding of the world around them and how to interpret the things that do not fit into what they already know.

This theory of developmental psychology has four stages. The first, sensorimotor, covers birth to age two and focuses on object permanence or realizing that an item still exists even when hidden from view. Next is the preoperational stage, from ages two to seven, where children learn to think symbolically by understanding that a thing can stand for something other than itself. The third stage is the concrete operational stage, from ages seven to 11. This is a turning point when logical thinking develops. Finally, the formal operational stage begins around age 11 and continues through adulthood. It concerns the ability to test hypotheses and think about abstract concepts.

Lev Vygotsky developed his theory of development around the same time Piaget was developing his. While Piaget believed that development must precede learning, Vygotsky believed that social learning comes before development. He placed a lot of emphasis on culture and social factors around the child rather than a child's ability to construct knowledge and believed that adults are an important source of support for cognitive development in children.

In addition to nature versus nurture, there are several other debates in developmental psychology that influence the way people think about the connection between the mind and body. One is reductionism versus holism, which argues that either behavior is best explained by breaking it down into small parts or by emphasizing the whole. Another is idiographic versus nomothetic, or whether to focus on generalizations or the things that make us unique.