1. Developmental psychology: the branch of psychology that studies the patterns of growth and change that occur throughout life.
2. Nature–nurture issue: the issue of the degree to which environment and heredity behaviour.
3. Identical twins: twins who are genetically identical.
4. Cross-sectional research: a research method that compares people of different ages at the same point at time.
5. Longitudinal research: a research method that investigates behaviour as participant age.
6. Sequential research: a research method that combines cross-sectional and longitudinal research by considering a number of different age groups and examining them at several points in time.
7. Chromosomes: rod-shaped structures that contain all basic heredity information.
8. Genes: the parts of the chromosomes through which genetic information is transmitted.
9. Zygote: the new cell formed by the union of an egg and sperm.
10. Embryo: a developed zygote that has a heart, a brain and other organs.
11. Fetus: a developing individual, from 8 weeks after conception until birth.
12. Age of viability: the point at which a fetus can survive if born prematurely.
13. Teratogens: environmental agents such as a drug, chemical, virus or other factor that produce a birth defect.
14. Neonate: a newborn child.
15. Reflexes: unlearned, involuntary responses that occur automatically in the presence of certain stimuli.
16. Habituation: the decrease in the response to a stimulus that occurs after repeated presentations of the same stimulus.
17. Attachment: the positive emotional bond that develops between a child and a particular individual.
18. Authoritarian parents: parents who are rigid and punitive and value unquestioning obedience from their children.
19. Permissive parents: parents who give their children relaxed or inconsistent direction and, although they are warm, require little of them.
20. Authoritative parents: parents who are firm, set clear limits, reason with their children and explain things to them.
21. Uninvolved parents: parents who show little interest in their children and are emotionally detached.
22. Temperament: basic, innate disposition.
23. Psychological development: development of individual‘s interactions and understanding of each other, and understanding of themselves as members of society.
24. Trust-versus-mistrust stage: according to Erikson, the first stage of psyhological development, occurring from birth to age 1,5 years, during which time infants develop feelings of trust or lack of trust.
25. Autonomy-versus-shame-and doubt stage: the period during which, according to Erikson, toddlers develop independence and autonomy if exploration and freedom are encouraged, or shame and self-doubt if they are restricted and overprotected.
26. Initiative-versus-guilt stage: according to Erikson, the period during which children ages 3 to 6 years experience conflict between independence of action and the sometimes negative results of that action.
27. Industry-versus inferiority stage: according to Erikson, the last stage of childhood, during which children age 6 to 12 years may develop positive social interactions with others or may feel inadequate and becomes less sociable.
28. Cognitive development: the process by which a child‘s understanding of the world changes as a function of age and experience.
29. Sensorimotor stage: according to Piaget, the stage from birth to 2 years, during which a child has little competence in representing the environment by using images, language or other symbols.
30. Object permanence: the awareness that objects and people continue to exist even if they are out of sight.
31. Preoperational stage: according to Piaget, the period from 2 to 7 years of age that is characterized by language development.
32. Egocentric thought: a way of thinking in which a child views the world entirely from his or her own perspective.
33. Principle of conversation: the knowledge that quantity is unrelated to the arrangement and physical appearance of objects.
34. Concrete operational stage: according to Piaget, the period from 7 to 12 years of age that is characterized by logical thought and a loss of egocentrism.
35. Formal operational stage: according to Piaget, the period from 12 to adulthood that is characterized by abstract thought.
36. Information processing: the way in which people take in, use and store information.
37. Metacognition: an awareness and understanding of one‘s own cognitive processes.
38. Zone of proximal development (ZPD): according to Vygotsky, the level at which a child can almost, but not fully, comprehend or perform a task on his or her own.
39. Adolescence: the developmental stage between childhood and adulthood.
40. Puberty: the period at which maturation of the sexual organs occurs, beginning at about age 11-12 for girls and 13-14 for boys.
41. Identity-versus-role-confusion stage: according to Erikson, a time in adolescence of major testing to determine one‘s unique qualities.
42. Identity: the distinguishing character of the individual: who each of us is, what our roles are, and what we are capable of.
43. Intimacy-versus-isolation stage: according to Erikson, a period during early adulthood that focuses on developing close relationships.
44. Generativity-versus-stagnation stage: according to Erikson, a period in middle adulthood during which we take stock of our contributions to family and society.
45. Ego-integrity-versus-despair stage: according to Erikson, a period from late a adulthood until death during which we review life‘s accomplishments and failures.
46. Menopause: the period during which women stop menstruating and are no longer fertile.
47. Genetic preprogramming theories of aging: theories that suggest that human cells have a built-in time limit to their reproduction, and that after a certain time they are no longer able to divide.
48. Wear and tear theories of aging: theories that suggest that the mechanical functions of the body simply stop working efficiently.
49. Alzheimer’s disease: a progressive brain disorder that leads to a gradual and irreversible decline cognitive abilities.
50. Disengagement theory of aging: a theory that suggests that aging produces a gradual withdrawal from the world on physical, psychological and social levels.
51. Activity theory of aging: a theory that suggests that the elderly who are most successful while aging are those who maintain the interests and activities they had during middle age.
52. Life review: the process by which people examine and evaluate their lives.