a branch of psychology that studies physical, cognitive, and social change throughout the life span.
the fertilized egg; it enters a 2-week period of rapid cell division and develops into an embryo.
the developing human organism from about 2 weeks after fertilization through the second month.
agents, such as chemicals and viruses, that can reach the embryo or fetus during prenatal development and cause harm.
fetal alcohol syndrome (FAS)
physical and cognitive abnormalities in children caused by a pregnant woman's heavy drinking. In severe cases, symptoms include noticeable facial misproportions.
decreasing responsiveness with repeated stimulation. As infants gain familiarity with repeated exposure to a visual stimulus, their interest wanes and they look away sooner.
biological growth processes that enable orderly changes in behavior, relatively uninfluenced by experience.
all the mental activities associated with thinking, knowing, remembering, and communicating.
the process by which the eye's lens changes shape to focus near or far objects on the retina.
in Piaget's theory, the stage (from birth to about 2 years of age) during which infants know the world mostly in terms of their sensory impressions and motor activities.
in Piaget's theory, the stage (from about 2 to 6 or 7 years of age) during which a child learns to use language but does not yet comprehend the mental operations of concrete logic.
the principle (which Piaget believed to be a part of concrete operational reasoning) that properties such as mass, volume, and number remain the same despite changes in the forms of objects.
in Piaget's theory, the preoperational child's difficulty taking another's point of view.
theory of mind
people's ideas about their own and others' mental states—about their feelings, perceptions, and thoughts, and the behaviors these might predict.
concrete operational stage
in Piaget's theory, the stage of cognitive development (from about 6 or 7 to 11 years of age) during which children gain the mental operations that enable them to think logically about concrete events.
formal operational stage
in Piaget's theory, the stage of cognitive development (normally beginning about age 12) during which people begin to think logically about abstract concepts.
a disorder that appears in childhood and is marked by deficient communication, social interaction, and understanding of others' states of mind.
the fear of strangers that infants commonly display, beginning by about 8 months of age.
an emotional tie with another person; shown in young children by their seeking closeness to the caregiver and showing distress on separation.
an optimal period shortly after birth when an organism's exposure to certain stimuli or experiences produces proper development.
the process by which certain animals form attachments during a critical period very early in life.
according to Erik Erikson, a sense that the world is predictable and trustworthy; said to be formed during infancy by appropriate experiences with responsive caregivers.
the transition period from childhood to adulthood, extending from puberty to independence.
primary sex characteristics
the body structures (ovaries, testes, and external genitalia) that make sexual reproduction possible.
secondary sex characteristics
nonreproductive sexual characteristics, such as female breasts and hips, male voice quality, and body hair.
our sense of self; according to Erikson, the adolescent's task is to solidify a sense of self by testing and integrating various roles.
the "we" aspect of our self-concept; the part of our answer to "Who am I?" that comes from our group memberships.
in Erikson's theory, the ability to form close, loving relationships; a primary developmental task in late adolescence and early adulthood.
for some people in modern cultures, a period from the late teens to early twenties, bridging the gap between adolescent dependence and full independence and responsible adulthood.
the time of natural cessation of menstruation; also refers to the biological changes a woman experiences as her ability to reproduce declines.
our ability to reason speedily and abstractly; tends to decrease during late adulthood.