Introduction to developmental psychology

• Developmental psychology is a discipline that attempts to describe and explain the changes that occur over time in the thought, behaviour, reasoning and functioning of a person due to biological, individual and environmental influences.
• Central questions in developmental psychology include Active vs Passive Child, Continuous vs Discontinuous development, Nature vs Nurture, Stability vs Change.
• John Locke (1632-1704) proposed the concept of the blank slate, stating that children are not born with any innate knowledge and that their knowledge is instead shaped by adult instruction.
• Jean-Jacques Rousseau (1712-1778) argued that children are not blank slates to be filled up by adult instruction, but rather "Noble Savages" with an innate plan for orderly, healthy growth.
• Rousseau introduced two influential concepts in developmental psychology: Stage and Maturation.
• For Rousseau, development was a discontinuous, stagewise process that follows a single, unified course mapped out by nature.
• The nature-nurture continuum is a central concept in developmental psychology, exploring the relative importance of innate factors (Core knowledge account) and experiential factors (Constructivist Accounts).
• Basic info about the world, particularly knowledge about the physical properties of objects, is available to the very young infant (Spelke and Baillargeon)
• Children construct their own knowledge, constructing new understanding of the world based on what they already know (Piaget)
• Piaget's theory of cognitive development is a significant contribution to developmental psychology.
• Some aspects of development are biological, such as puberty, which can be affected by environmental factors like diet.
• Most psychologists believe in an interaction between biological and environmental forces that causes development.
• In some cases, the interactions are very complex, such as language.
• Reciprocal interaction refers to dependency and interaction across different modalities and areas of development.
• Techniques used in developmental research include cross-sectional (between subjects design), longitudinal (within subjects design), experimental, clinical, neuroimaging, and case studies.
• Within-subjects design involves the same group of individuals, and measures them more than once over a period of time, typically for a Longitudinal Study.
• Within-subject design helps us to determine if development is continuous or discontinuous.
• Sampling time can impact our conclusions.
• An example of a research study using a combination of maturation effects and impact of therapy on outcome scores is demonstrated.
• The therapy study demonstrates a clear maturation effect which poses a threat to conclusions regarding the impact of therapy.
• Longitudinal studies have strengths such as no problem with individual differences and continuity, but also have weaknesses like expenses (especially time), difficulty chasing-up participants after many years, and participant attrition/selective survivorship.
• Between-subjects design compares two or more separate groups of individuals.
• In a between-subjects design, we can compare the performance of two groups such as typical vs atypical development or two different age groups, which is an example of a cross-sectional research design.
• Cross-sectional studies have strengths like not taking long to collect data and not having a problem with attrition, but also have weaknesses like not providing continuity and describing age differences, not change.
• Sequential design is a combination of longitudinal and cross-sectional designs.
• A second time stamp can be added to complete a between and within subjects design.
• Research into Visual Performance (IQ) and Age uses a sequential design to uncover differing results from longitudinal and cross-sectional data.
• Cohort effects are a type of research design where different groups of people are studied at different times.
• Developmental Theories focus on changes in behaviour over time and explain how these changes take place.
• Good theories should be testable, refutable, modifiable and reliable.
• Sigmund Freud (1856-1939) proposed that unconscious motives control our behaviour and feelings.
• According to Freud, personality is made up of three structures: ID (pleasure principle), Ego (conflict with reality, ego emerges), and Superego (internalise parental and society values).
• In Freud's Psychodynamic theory, behaviour is motivated by two instinctual drives stemming from the ID: Eros (sex drive and life instinct) and Thanatos (the aggressive drive and death instinct).
• Freud's Psychodynamic theory includes five stages of development: Oral (0-18 months), Anal (18 months to 3 years), Phallic (3 years to 5 or 6 years), Latency (middle childhood), and Genital (adolescence).
• During each stage of Freud's Psychodynamic theory, the growing person must resolve conflicts between what the Id wants and what the environment will provide.
• Where a conflict is not adequately resolved, a fixation develops which is then thought to influence the person’s functioning later in life.
• Erikson’s Psychosocial Theory emphasises the role of social and cultural factors and proposes development continues through out age.
• Erikson's Psychosocial Theory includes 8 stages of development from birth to adulthood.
• Each stage of Erikson's Psychosocial Theory appears in a set order and is built upon each other.
• Each stage of Erikson's Psychosocial Theory is focused on a specific challenge or crisis that need to be resolved to move on to the next stage of development.