Psychoanalytic Theories. These illustrate the importance of early experience in personality development and the role of unconscious motivation. Freud's psychosexual stages, as well as Erikson's psychosocial stages of development, are examined within this context.

Behavioural Theory. This stresses the part that learning plays in inducing individuals to act in the ways that they do. Skinner's basic tenets in regard to this perspective are highlighted.

Humanistic Theory. This emphasizes that people are capable of intervening in the flow of life's experiences to influence and fashion their own beings. Discussion centers on the viewpoints of Maslow and Rogers.

Cognitive Theory. This draws our attention to the importance of various mental capabilities and problem-solving skills that equip people with potent adaptive skills. Piaget's cognitive stages are examined within this context.

Evolutionary Adaptation Theory. This highlights various biological patterns that ready individuals for specific kinds of behaviour.

Controversies. Several important controversies are presented, which increase one's understanding of the distinctions among the major theories of human development. (mechanistic an organismic models; continuity and discontinuity in development; nature-nurture controversies (heredity vs. environment) – twins study; behavioural genetics)

Box: Jerome Kagan on the Early Years (village in Guatemala) – child’s experience can slow down or speed up the emergence of basic abilities by several months or even years  => children biologically pre-programmed with basic mental competences that equips them with essentials for perceptual and intellectual functioning

Summary

1. Theory is a tool that allows us to organize a large array of facts so that we can understand them. To understand how nature works is to gain the prospect of securing some control over our destiny.

2. Sigmund Freud postulated that all human beings pass through a series of psychosexual stages: oral, anal, phallic, latency, and genital. Each stage poses a unique conflict that the individual must resolve before passing on to the next stage.

3. Critics complain that Freudian theory is difficult to evaluate because it makes few predictions that can be tested by accepted scientific procedures. Nonetheless, Freud's work is generally regarded as a revolutionary milestone in the history of human thought.

4. Erik Erikson, a theorist in the psychoanalytic tradition, identifies eight psychosocial stages, each of which confronts the individual with a major conflict that must be successfully resolved if healthy development is to occur. Erikson's theory draws our attention to the continual process of personality development that takes place throughout an entire person's life span. (epigenetic principle – anything that grows has a ground plan, each parts have arisen to form a functioning whole)

5. Behavioural theory stands in sharp contrast to psychoanalytic theory. Its proponents believe that if psychology is to be a science, it must not rely on introspection but must look to data that are directly observable and measurable.

6. Behaviourists are especially interested in how people learn to behave in particular ways. They deem learning to be a process whereby individuals, as a result of their experience, establish an association or linkage between two events, a process called "conditioning." Behaviourists divide the environment into units termed "stimuli" and the behaviour elicited by stimuli into units termed "responses."

7. Humanistic psychology – also called "thirdforce" psychology – has arisen in reaction to psychoanalysis and behaviourism. It maintains that human beings are different from all other organisms in that they actively intervene in the course of events to control their destinies and to shape the world around them. Its proponents seek to maximize the human potential for self-direction and freedom of choice.

8. Jean Piaget has come to be recognized as a giant of twentieth-century psychology. For Piaget the critical question in the study of growing children is how they adjust to the world they live in. Scheme, assimilation, accommodation, and equilibrium are key concepts in Paigetian theory. They find expression in four stages of cognitive development: the sensorimotor stage, the preoperational stage, the stage of concrete operations, and the stage of formal operations.

9. Cognitive learning theorists say that our capacity to use symbols affords us a powerful means for comprehending and dealing with our environment. Verbal and imagined symbols allow us to represent events; to analyze our conscious experience; to communicate with others; to plan, to create, to imagine; and to engage in foresightful action.

10. Evolutionary adaptation theory studies the behaviour patterns of organisms from a biological point of view. Its proponents rely heavily on the evolutionary theory of Charles Darwin. Ethologists say that evolution applies not only to anatomy and physiology but also to predispositions for certain types of behaviour. Organisms are said to be genetically prepared for some responses.

11. Each of the five major types of theory we considered has its proponents and critics. Yet the theories are not mutually exclusive; we need not accept one and reject the others. Different tasks simply call for different theories. Thus, most psychologists prefer an eclectic approach to development.

12. When scientists came to recognize the inappropriateness of the "which" question, some of them took a somewhat different approach. They sought to establish how much of the observed differences among people are due to heredity and how much to differences in environment. Recently, a number of scientists have argued that the "how much" question, like the "which" question, leads to no productive end. They have insisted that a more fruitful approach is to be found in the question of how specific hereditary and environmental factors work together to influence various characteristics.

13. New and valuable insights are coming from a rapidly growing field of study that undertakes to embrace, forge, and integrate insights from both psychology and genetics – behavioural genetics. Jerome Kagan and his associates have shown the part genetic factors play in extreme timidity. Researchers at the University of Minnesota have similarly examined how genetic makeup impacts personality.