zygote
the fertilized egg; it enters a 2-week period of rapid cell division and develops into an embryo
embryo
the developing human organism from about 2 week after fertilization through the second month
fetus
the developing human organism from 9 weeks after conception to birth
teratogens
monster maker; 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 pregnant woman’s heavy drinking
habituation
decreasing responsiveness with repeated stimulation
maturation
biological growth processes that enable orderly changes in behavior, relatively uninfluenced by experience
schema
a concept or framework that organizes and interprets information
assimilation
interpreting our new experiences in terms of our existing schemas
accommodation
adapting our current understandings (schemas) to incorporate new information
sensorimotor stage
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
object permanence
the awareness that things continue to exist even when not perceived
preoperational stage
in Piaget’s theory, the stage (from about 2 to about 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
conservation
the principle that properties such as mass, volume, and number remain the same despite changes in the forms of objects
egocentrism
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 other’s mental states -- about their feelings, perceptions, and thoughts, and the behaviors these might predict
autism spectrum disorder (ASD)
a disorder that appears in childhood and is marked by significant deficiencies in communication and social interaction, and by rigidly fixated interests and repetitive behaviors
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
stranger anxiety
the fear of strangers that infants commonly display, beginning by about 8 months of age
attachment
an emotional tie with another person
critical period
an optimal period early in the life of an organism when exposure to certain stimuli or experiences produces normal development
imprinting
the process by which certain animals form strong attachments during an early-life critical period
temperament
a person’s characteristic emotional reactivity and intensity
basic trust
according to Erik Erikson, a sense that the world is predictable and trustworthy
self-concept
all our thoughts and feelings about ourselves, in answer to the questions, “Who am I?”
gender
the socially constructed roles and characteristics by which a culture defines male and female
aggression
any physical or verbal behavior intended to hurt or destroy
gender role
a set of expected behaviors for males and for females
role
a set of expectations (norms) about a social position, defining how those in the position ought to behave
gender identity
our sense of being male or female
social learning theory
the theory that we learn social behavior by observing and imitating and by being rewarded or punished
gender typing
the acquisition of a traditional masculine or feminine role
transgender
an umbrella term describing people whose gender identity or expression differs from that associated with their birth sex
adolescence
the transition period from childhood to adulthood, extending from puberty to independence
identity
our sense of self
social identity
the “we” aspect of our self-concept
intimacy
in Eriksons’s theory, the ability to form close, loving relationships; a primary developmental task in late adolescence and early adulthood
emerging adulthood
for some people in modern cultures, a period from the late teens to mid-twenties, bridging the gap between adolescent dependence and full independence and responsible adulthood
X chromosome
the sex chromosome found in both men and women (females have two, males have one; an X chromosome from each parent produces a female child)
Y chromosome
the sex chromosome found only in males (when paired with an X chromosome from the mother, it produces a male child)
testosterone
the most important of the male sex hormones
puberty
the period of sexual maturation, during which a person becomes capable of reproducing
primary sex characteristics
the body structures that make sexual reproduction possible (ovaries, testes, & external genitalia)
secondary sex characteristics
nonreproductive sexual traits, such as female breasts and hips, male voice quality, and body hair
menarche
the first menstrual period
AIDS (acquired immune deficiency syndrome)
a life-threatening, sexually transmitted infection caused by the human immunodeficiency virus; depletes the immune system, leaving the person vulnerable to infection
sexual orientation
an enduring sexual attraction toward members of either one’s own sex, the other sex, or both sexes
menopause
the time of natural cessation of menstruation; also refers to the biological changes a woman experiences as her ability to reproduces declines
cross-sectional study
a study in which people of different ages are compared with one another
longitudinal study
research in which the same people are restudied and retested over a long period
social clock
the culturally preferred timing of social events such as marriage, parenthood, and retirement