Developmental Psychology: Theories, Methods, and Key Concepts

Developmental Psychology

The scientific study of how and why human beings change over the course of their life.

Genotype

The genetic constitution of an individual, which determines specific traits.

Phenotype

The observable physical or biochemical characteristics of an organism, determined by both genotype and environment.

Heredity

The passing of traits from parents to offspring through genes.

Environment

All external factors that influence an individual's development, including social, cultural, and physical conditions.

Gene-environment interaction

The complex interplay between genetic predispositions and environmental influences on development.

Assimilation

The process of incorporating new information into existing cognitive schemas.

Accommodation

The process of altering cognitive schemas to incorporate new information.

Sensorimotor stage

The first stage in Piaget's theory of cognitive development, occurring from birth to about 2 years, where infants learn through sensory experiences and manipulating objects.

Object permanence

The understanding that objects continue to exist even when they cannot be seen or heard, typically developed by infants around 8-12 months.

Deferred imitation

The ability to remember and replicate an observed behavior after a delay.

Information processing

A cognitive approach that compares the human mind to a computer, focusing on how information is encoded, stored, and retrieved.

A-not-B task

A test used to assess an infant's understanding of object permanence and their ability to track the location of an object.

Trust vs. Mistrust

Erikson's first psychosocial stage, where infants learn to trust caregivers for basic needs or develop mistrust if these needs are not met.

Autonomy vs. Shame & Doubt

Erikson's second psychosocial stage, where toddlers learn to assert their independence or feel shame and doubt about their abilities.

Receptive language

The ability to understand language and communicate effectively.

Productive language

The ability to produce language, including speaking and writing.

Holophrase

A single word used by an infant to express a complete idea or sentiment.

Joint attention

A social-communication skill where two people use gestures and gaze to share focus on an object.

Fast mapping

The process by which children quickly learn new words and associate them with their meanings after only a brief exposure.

Underextension

A language error where a child uses a word too narrowly, applying it to fewer objects than it actually represents.

Overextension

A language error where a child uses a word too broadly, applying it to more objects than it actually represents.

Telegraphic speech

Early speech stage in which a child speaks using two or three words that convey a complete thought.

Zygote

The fertilized egg that results from the union of sperm and egg, which develops into an embryo.

Germinal period

The first two weeks of prenatal development after conception, during which the zygote divides and implants in the uterine wall.

Embryonic period

The stage of prenatal development from the third to the eighth week, during which major organs and structures begin to form.

Fetal period

The stage of prenatal development from the ninth week until birth, characterized by growth and maturation of the developing fetus.

Teratogen

An environmental agent that can cause harm to a developing fetus, leading to birth defects.

Low birthweight

A term used to describe babies who are born weighing less than 5.5 pounds, which can lead to health complications.

Prematurity

The condition of being born before the 37th week of pregnancy, which can result in various health issues.

Restricted fetal growth

A condition where a fetus does not grow to its expected size during pregnancy, often leading to low birthweight.

Small for gestational age

A term used to describe infants whose weight is below the 10th percentile for their gestational age.

Apgar

A quick assessment of a newborn's health, measuring heart rate, breathing, muscle tone, reflex response, and color.

Correlation

A statistical measure that indicates the extent to which two variables fluctuate together.

Causation

The relationship between cause and effect, where one event (the cause) directly affects another event (the effect).

Independent variable

The variable that is manipulated in an experiment to observe its effect on the dependent variable.

Dependent variable

The variable that is measured in an experiment to see how it is affected by changes in the independent variable.

Random assignment

The process of randomly assigning participants to different groups in an experiment to ensure that each group is similar.

Experimental and control groups

The experimental group receives the treatment, while the control group does not, allowing for comparison.

Cross-sectional design

A research method that compares different groups of individuals at one point in time.

Longitudinal design

A research method that studies the same group of individuals over an extended period.

Sequential design

A research method that combines cross-sectional and longitudinal designs by studying different age groups over time.

Reliability

The consistency of a measure, indicating that it produces stable and consistent results over time.

Validity

The extent to which a test measures what it claims to measure.

Synaptogenesis

The formation of synapses between neurons in the nervous system, crucial for brain development.

Synaptic pruning

The process of eliminating weaker synaptic connections while strengthening others, improving brain efficiency.

Myelination

The process of forming a myelin sheath around the axons of neurons, which increases the speed of neural transmission.

Developmental milestones

Key skills or behaviors that are expected to be achieved by certain ages in a child's development.

Dynamic systems theory

A theoretical framework that views development as a complex, adaptive process influenced by multiple factors.

Habituation

A decrease in response to a stimulus after repeated presentations, indicating learning and memory.

Dishabituation

The increase in response to a stimulus after a change in the stimulus, indicating renewed interest.

Perceptual narrowing

The developmental process where infants become more attuned to the stimuli they encounter frequently, often leading to a decline in sensitivity to less familiar stimuli.

Basic emotions

Innate emotions that are universally recognized, such as happiness, sadness, fear, anger, surprise, and disgust.

Self-conscious emotions

Emotions that require self-awareness and social understanding, such as guilt, shame, and embarrassment.

Social referencing

The process by which infants look to caregivers for cues on how to react to unfamiliar situations.

Temperament

An individual's characteristic pattern of emotional reactivity and self-regulation.

Goodness of fit

The compatibility between a child's temperament and the demands of their environment, influencing development.

Attachment

The emotional bond that forms between a child and their caregiver, crucial for social and emotional development.

Secure base

A caregiver's presence that provides a child with the confidence to explore their environment.

Strange Situation

A standardized procedure for assessing attachment in infants by observing their reactions to separations and reunions with their caregiver.

Secure attachment

A strong emotional bond characterized by trust and a sense of safety in the relationship with the caregiver.

Insecure-avoidant attachment

A type of attachment where infants show little distress when separated from the caregiver and avoid contact upon reunion.

Insecure-resistant attachment

A type of attachment where infants are highly distressed during separation and show ambivalence upon reunion.

Insecure-disorganized attachment

A type of attachment characterized by a lack of clear attachment behavior, often resulting from inconsistent caregiver responses.

Caregiver sensitivity

The ability of a caregiver to perceive and respond appropriately to a child's needs, influencing attachment security.