Nature vs. Nurture

• Nature versus nurture controversy: dealing with the extent to which heredity and the environment each influences behavior.

• Maturation: biological growth processes that bring about orderly changes in behavior, thought, or physical growth, relatively unaffected by experience.

• Continuity versus discontinuity: deals with the question of whether development is gradual, cumulative change from conception to death (continuity), or a sequence of distinct stages (discontinuity).

  • quantitative changes in number or amount, such as changes in height and weight.

  • qualitative changes in kind, structure, or organization.

• Stability versus change: deals with the issue of whether or not personality traits present during infancy endure throughout the lifespan.

• Longitudinal Studies:  follows the same group of people over a period from months to many years in order to evaluate changes in those individuals.

• Cross-sectional study: researchers assess developmental changes with respect to a particular factor by evaluating different age groups of people at the same time. Cross-sectional studies can be invalid if a cohort, group of people in one age group, is significantly different in their experiences from other age groups, resulting in the cohort effect, differences in the experiences of each age group as a result of growing up in different historical times.

• Cohort-sequential studies: cross-sectional groups are assessed at least two times over a span of months or years, rather than just once.

• Biographical or retrospective studies: are case studies that investigate development in one person at a time.

Physical Development

• Physical development: focuses on maturation and critical periods.

• Critical period: is a time interval during which specific stimuli have a major effect on development that the stimuli do not produce at other times.

Prenatal Development

• Prenatal development begins with fertilization, or conception, and ends with birth.

• The zygote is a fertilized ovum with the genetic instructions for a new individual normally contained in 46 chromosomes.

• Different genes function in cells of the three different layers; the forming individual is now considered an embryo.

• Fetus: the developing human organism from about 9 weeks after conception to birth.

Birth Defects

• Teratogens:  Chemicals such as alcohol, drugs, tobacco ingredients, mercury, lead, cadmium, and other poisons or infectious agents, such as viruses, that cause birth defects

• Fetal alcohol syndrome (FAS): is a cluster of abnormalities that occurs in babies of mothers who drink alcoholic beverages during pregnancy.

Behavior of the Neonate

• Neonates: or newborn babies, are equipped with basic reflexes that increase their chances of survival.

• Rooting: is the neonate’s response of turning his or her head when touched on the cheek and then trying to put the stimulus into his or her mouth.

• Sucking is the automatic response of drawing in anything at the mouth.

• Swallowing is a contraction of throat muscles that enables food to pass into the esophagus without the neonate choking.

• Grasping reflex: when the infant closes his or her fingers tightly around an object put in his or her hand.

• Moro or startle reflex: in which a loud noise or sudden drop causes the neonate to automatically arch his or her back, fling his/her limbs out, and quickly retract them.

• Habituation: is decreasing responsiveness with repeated presentation of the same stimulus.

The First 2 Years

• The first two years of an infant's physical development are amazing.

• From the prenatal period, when about 20 billion brain cells are produced, to the first two years, when dendrites proliferate in neural networks, especially in the cerebellum, then in the occipital and temporal lobes as cognitive abilities grow, brain development proceeds rapidly.

• The head becomes less out of proportion as the torso and limbs grow faster.

• The nervous system matures while the musculoskeletal system develops from head to tail and from the center outward, allowing the baby to lift its head, roll over, sit, creep, stand, and walk, usually in that order.

• New behaviors develop from maturity, motor and perceptual skills, motivation, and environmental support.

• In the frontal cortex, dendrites proliferate rapidly during childhood.

Adolescence

• Puberty: is sexual maturation, marked by the onset of the ability to reproduce.

• Primary sex characteristics: reproductive organs (ovaries and testes) start producing mature sex cells, and external genitals (vulva and penis) grow.

• Secondary sex characteristics: nonreproductive features associated with sexual maturity—such as widening of hips and breast development in females; growth of facial hair, muscular growth, development of the “Adam’s apple,” and deepening of the voice in males; and growth of pubic hair and underarm hair in both.

• Adolescence involves selective pruning of unused dendrites, emotional limbic system development, and frontal lobe maturation.

  • The judgment and decision-making prefrontal/frontal cortex matures into early adulthood.

  • The prefrontal cortex has not had enough time to develop, so this disconnect between physical and mental maturation can cause risky behavior.

Aging

• By our mid-20s, our physical capabilities peak, followed by first almost imperceptible, then accelerating, decline.

• According to evolutionary psychologists, peaking at a time when both males and females can provide for their children maximizes chances of survival for our species.

• Decreased vigor, changes in fat distribution, loss of hair pigmentation, and wrinkling of the skin are changes associated with advances in age.

• In females at about age 50, menopause—cessation of the ability to reproduce—is accompanied by a decrease in production of female sex hormones.

• Men experience less frequent erections and a more gradual decline in reproductive function as they age.

Theories of Cognitive Development

Jean Piaget’s Theory of Cognitive Development

• Swiss psychologist Jean Piaget developed a stage theory of cognitive development based on decades of careful observation and testing of children.

• Piaget believed that all knowledge begins with building blocks called schemas, mental representations that organize and categorize information processed by our brain.

• Through the process of assimilation, we fit new information into our existing schemas.

• Through the process of accommodation we modify our schemas to fit new information.

Sensorimotor (First) Stage

• Birth to 2 years old

• During which the baby explores the world using his or her senses and motor interactions with objects in the environment.

• The concept of object permanence—that objects continue to exist even when out of sight—to Piaget seemed to develop suddenly between 8 and 10 months.

• Stranger anxiety: fear of unfamiliar people, indicating that they can differentiate among people they know and people they don’t know.

Preoperational (Second) Stage

• 2-7 years old.

• The child is mainly egocentric, seeing the world from his or her own point of view.

• Egocentrism: is consistent with a belief called animism, that all things are living just like him or her and the belief, called artificialism, that all objects are made by people.

Concrete Operational (Third) Stage

• 7-12 years old

• Conservation concepts: in which changes in the form of an object do not alter physical properties of mass, volume, and number.

Formal Operational (Fourth) Stage

• In this stage, youngsters are able to think abstractly and hypothetically.

• They can manipulate more information in their heads and make inferences they were unable to make during the previous stage.

Vygotsky’s Sociocultural Theory of Cognitive Development

• Russian psychologist Lev Vygotsky emphasized the role of the environment (nurture) and gradual growth (continuity) in intellectual functioning.

• Vygotsky thought that development proceeds mainly from the outside in by the process of internalization, absorbing information from a specified social environmental context.

• Zone of proximal development (ZPD): the range between the level at which a child can solve a problem working alone with difficulty and the level at which a child can solve a problem with the assistance of adults or more-skilled children.

Cognitive Changes in Adults

• Fluid intelligence: those abilities requiring speed or rapid learning—generally diminishes with aging

• Crystallized intelligence: learned knowledge and skills such as vocabulary—generally improves with age (at least through the 60s).

Theories of Moral Development

• Lawrence Kohlberg: like Piaget, thought that moral thinking develops sequentially in stages as cognitive abilities develop.

• Preconventional level of morality: in which they do the right thing to avoid punishment (stage 1) or to further their self-interests (stage 2).

• Conventional level of morality: in which they follow rules to live up to the expectations of others, “good boy/nice girl” (stage 3), or to maintain “law and order” and do their duty (stage 4).

• Postconventional level of morality: in which they evidence a social contract orientation that promotes the society’s welfare (stage 5) or evidence an ethical principle orientation that promotes justice and avoids self-condemnation (stage 6).

• Carol Gilligan: found that women rarely reach the highest stages of morality, because they think more about the caring thing to do or following an ethic of care, rather than what the rules allow or following an ethic of justice.

Theories of Social and Emotional Development

• Theories of social development look at the influence of others on the development of a person.

  • Others include members of the family and other caregivers, peers, and even culture, which consists of the behaviors, ideas, attitudes, and traditions transmitted from one generation to the next within a group of people who share the same language and environment.

• Bonding: is the creation of a close emotional relationship between the mother (or parents) and baby shortly after birth.

• Attachment: As the mother (or other caregiver) bonds with the infant, through frequent interactions, the infant gradually forms a close emotional relationship with his or her mother (or other caregivers)

• Harry Harlow’s: experimental research with monkeys disproved that belief when he found that baby monkeys separated from their mothers preferred to spend time with and sought comfort from a soft cloth-covered substitute (surrogate) rather than a bare wire substitute with a feeding bottle.

• Mary Ainsworth: studied attachment using a “strange situation” where a mother and baby play in an unfamiliar room, the baby interacts with the mother and an unfamiliar woman, the mother leaves the baby with the other woman briefly, the baby is left alone briefly, and then the mother returns to the room.

• Temperament: or natural disposition to show a particular mood  at a particular intensity for a specific period, affects his or her behavior.

• Self-awareness: consciousness of oneself as a person, and social referencing, observing the behavior of others in social situations to obtain information or guidance, both develop between ages 1 and 2.

Parenting Styles

• Diana Baumrind: studied how parenting styles affect the emotional growth of children.

• Authoritarian: parents set up strict rules, expect children to follow them, and punish wrongdoing.

• Authoritative: parents set limits but explain the reasons for rules with their children and make exceptions when appropriate.

• Permissive: parents tend not to set firm guidelines, if they set any at all.

• Uninvolved: parents make few demands, show low responsiveness, and communicate little with their children.

Erikson’s Stage Theory of Psychosocial Development

• Erik Erikson: was an influential theorist partly because he examined development across the life span in a social context, rather than just during childhood, recognizing that we continue to grow beyond our teenage years, and our growth is influenced by others.

• His stage theory of psychosocial development identifies eight stages during which we face an important issue or crisis.

Middle Age and Death

• Daniel Levinson: described a midlife transition period at about age 40, seen by some as a last chance to achieve their goals.

  • People who experience anxiety, instability, and change about themselves, their work, and their relationships during this time have a challenging experience sometimes termed the mid-life crisis.

• Psychiatrist Elisabeth Kübler-Ross’s studies of death and dying have focused attention on the end of life, encouraging further studies of death and dying and the growth of the hospice movement that treats terminal patients and their families to alleviate physical and emotional pain.

Gender Roles and Sex Differences

• Gender: is the sociocultural dimension of being biologically male or female.

• Gender roles: are sets of expectations that prescribe how males and females should act, think, and feel.

• Gender identity: is our sense of being male or female, usually linked to our anatomy and physiology.

• Biopsychosocial model: ascribes gender, gender roles, and gender identity to the interaction of heredity (biology) and environment (including psychological and social-cultural factors).

• Biological Perspective: The biological perspective attributes differences between the sexes to heredity.

• Evolutionary Perspective: According to the evolutionary perspective, our behavioral tendencies prepare us to survive and reproduce.

• Psychoanalytic Perspective: According to Freud’s psychoanalytic perspective, young girls learn to act feminine from their mothers, and young boys learn to act masculine from their fathers when they identify with their same-sex parent as a result of resolving either the Electra or Oedipal complex at about age 5.

• Behavioral Perspective: According to (the behavioral perspective) social learning theory, children respond to rewards and punishments for their behavior, and they observe and imitate significant role models, such as their parents, to acquire their gender identity.

• Cognitive Perspective: According to the cognitive perspective,  children actively engage in making meaning out of information they learn about gender.

  • Sandra Bem’s gender schema theory says that children form a schema of gender that filters their perceptions of the world according to what is appropriate for males and what is appropriate for females.

• Gender role stereotypes: which are broad categories that reflect our impressions and beliefs about males and females, have typically classified instrumental traits, such as self-reliance and leadership ability, as masculine and expressive traits, such as warmth and understanding, as feminine.

• Androgyny: the presence of desirable masculine and feminine characteristics in the same individual.

Sex Differences in Cognition

• Meta-analysis: of research on gender comparisons indicates that, for cognitive skills, the differences within either gender are larger than the differences between the two genders.

• Stereotype threat: anxiety that influences members of a group concerned that their performance will confirm a negative stereotype.