The study of continuity & change across the lifespan.
Developmental psychology
A fertilized egg that contains chromosomes from both a sperm and an egg.
Zygote
The 2-week period of prenatal development that begins at conception.
Germinal stage
The period of pernatal development that lasts from the second week until about the 8th week.
Embryonic stage
The period of prenatal development that lasts from 9th week till birth.
Fetal stage
The formation of a fatty sheath around the axon of a neuron.
Myelination
Agents that damage the process of development such as drugs & viruses.
Teratogens
A developmental disorder that stems from heavy alcohol use by the mother during pregnancy.
Fetal alcohol syndrome
The stage of development that begins at birth & lasts between 18 & 24 months.
Infancy
The emergence of the ability to execute physical action.
Motor development
Specific patterns of motor responses that are triggered by specific patterns of sensory stimulation.
Reflexes
The "top-to-bottom" rule that describes the tendency for motor skills to emerge in sequence from the head to the feet.
Cephalocaudal rule
The "inside-to-outside" rule that describes the tendency for motor skills to emerge in sequence from the center to the periphery.
Proximodistal rule
The emergence of the ability to think and understand.
Cognitive development
A stage of development that begins at birth and lasts through infancy in which the infant aquires information about the world by sensing it and moving around within it.
Sensorimotor stage
Theories about or models of the way the world works.
Schemas
The process by which infants apply their schemas in novel situations.
Assimilation
The process by which infants revise their schemas in light of new information.
Accomodation
The idea that objects continue to exist even when they aren't visible.
Object permanence
The stage of development that begins at about 18 to 24 months and lasts until adolescence.
Childhood
The stage of development that begins at about 2 years and ends at about 6 years in which children have a preliminary understanding of the physical world.
Preoperational stage
The stage of development that begins at about 6 years & ends at about 11 years, in which children learn how various actions or "operations" can affect or transorm "concrete" objects.
Concrete operational stage
The notion that the quantitative properties of an object are invariant despite changes in the object's appearance.
Conservation
The stage of development that begins around the age of 11 & lasts through adulthood, in which people can solve nonphysical problems.
Formal operational stage
The failure to understand that the world appears differently to different observers.
Egocentrism
The idea that human behavior is guided by mental representations.
Theory of mind
The emotional bond that forms between newborns & their primary caregivers.
Attachment
A behavioral test developed by Mary Ainsworth that is used to determine a child's attachment style.
Strange situation
A set of beliefs about the self, the primary caregiver, and the relation between them.
Internal working model of relationships
Characteristc patterns of emotional reactivity.
Temperaments
A stage of moral development in which the morality of an action is primarily determined by its consequenses for the actor.
Preconventional stage
A stage of moral development in which the morality of an action is primarly determined by the extent to which it conforms to social rules.
Conventional stage
A stage of moral development at which the morality of an action is determined by a set of general principles that reflect core values.
Postconventional stage
The period of development that begins with the onset of sexual maturity (about 11 to 14 years of age) and lasts until the beginning of adulthood (about 18 to 21 years of age).
Adolescence
The bodily changes associated with sexual maturity.
Puberty
Bodily structures that are directly involved in reproduction.
Primary sex characteristics
Bodily structures that change dramatically with sexual maturity but that are not directly involved in reproduction.
Secondary sex characteristics
The stage of development that begins around 18 to 21 and ends at death.