The debate over the extent to which human behavior is determined by genetics and the environment.
A method of testing nature and nurture by comparing pairs of identical and fraternal twins of the same sex.
A method of testing nature and nurture by comparing twins and other siblings reared together with those separated by adoption.
A statistical estimate of the percentage of the variability of a trait within a group that is attributable to genetic factors.
A method of developmental research in which people of different ages are tested and compared.
A method of developmental research in which the same prople are tested at different times to track changes related to age.
Rod-like structures, found in all biological cells, that contain DNA molecules in the form of genes.
deoxyribonucleic acid (DNA)
The complex molecular structure of a chromosome that carries genetic information.
A fertilized egg that undergoes a two-week period of rapid cell division and develops into an embryo
fetal alcohol syndrome (FAS)
A specific pattern of birth defects (stunted grown, facial deformity, and mental retardation) often found in the offspring of alcoholic mothers.
The tendency for attention to a stimulus to wane over time (often used to determine whether an infant has "learned" a stimulus.
Following habituation to one stimulus, the tendency for a second stimulus to arouse new interest (often used to test whether infants can discriminate between stimuli)
In response to contact on the cheek, an infant's tendency to turn toward the stimulus and open its mouth.
In Piaget's theory, mental representations of the world that guide the processes of assimilation and accommodation.
In Piaget's theory, the process of incorporating and, if necessary, changing new information to fit existing cognitive structures.
In Piaget's theory, the process of modifying existing cognitive structures in response to new information.
Piaget's first stage of cognitive development, from birth to two years old, when infants come to know, the world through their own actions.
Developing at six to eight months, an awareness that objects continue to exist after they disappear from view.
Among infants with object permanence, a fear reaction to the absence of their primary caretaker.
Piaget's second stage of cognitive development, when two to six year olds become capable of reasoning in an intuitive, prelogical manner
Te concept that physical properties of an object remain the same despite superficial changes in appearance.
concrete operational stage
Piaget's third stage of cognitive development, when six year olds become capable of logical reasoning.
formal operational stage
Piaget's fourth stage of cognitive development, when adolescents become capable of logic and abstract thought.
Spontaneous vocalizations of basic speech sounds, which infants begin at about four months of age.
Early short form of speech in which the child omits unnecessary words--as telegrams once did ("More milk")
A period of time during which an organism must be exposed to a certain stimulus for proper development to occur.
A parent-infant "separation and reunion" procecure that is staged in a laboratory to test the security of a child's attachment.
A parent-infant relationship in which the baby is secure when the parent is present, distressed by separation, and delighted by reunion.