Chapter 9Lifespan and Development

GeneticsHumans have 23 pairs of chromosomes.

Chromosomes: long thread-like structure composed of twisted parallel strands of DNA.

DNA is the chemical basis of heredity and carries instructions.Genes are the basic unit of heredity; single unit of DNA on the chromosome.Allele: One of the different forms of a particular gene.Sex Chromosomes: Chromosomes designated as X or Y, that determine biological sex; 23rd pair of chromosomes.

Dominant and Recessive GenesGenotype—underlying genetic makeup (what you get from your parents)Phenotype—traits that are expressed (result of environmental factors)Dominant genes—will always be expressed if presentRecessive genes—will not be expressed unless they are in a pair

EpigeneticsThe study of the mechanisms that control gene expression and its effects on behavior and health.Gene expression is flexible.

Prenatal DevelopmentConception—when a sperm penetrates the ovumZygote—a fertilized eggGerminal period—first two weeks after conceptionEmbryonic period—weeks three through eight after conceptionFetal period—two months after conception until birth Stem Cells: cells that can divide indefinitely, renew themselves, and develop into any one of the body’s different cell types.

Prenatal Influences on DevelopmentNutritionAnxietyMother’s general healthMaternal ageTeratogens—any agent that causes a birth defect (e.g., drugs, radiation, viruses)

Infant AbilitiesInfants are born with immature visual system

can detect movement and large objects

Can hear Turn away from unpleasant odors Prefer sweet to sour tastesTouch and pain is highly functional

Infant ReflexesRooting—turning the head and opening the mouth in the direction of a touch on the cheek

Sucking—sucking rhythmically in response to oral stimulation

Babinski—fanning and curling toes when foot is stroked

Moro—throwing the arms out, arching the back and bringing the arms together as if to hold onto something (in response to loud noise or sudden change in position of the head)

Grasping—curling the fingers around an object

TemperamentEasy—adaptable, positive mood, regular habitsSlow to warm up—low activity, somewhat slow to adapt, generally withdraw from new situationsDifficult—intense emotions, irritable, cry frequentlyAverage—unable to classify (1/3 of all children)

AttachmentEmotional bond that forms between an infant and caregiver, especially the parents.

Securely attached—explores the room when mother is present, becomes upset and explores less when mother is not present, shows pleasure when mother returns

Avoidantly attached—a form of insecure attachment in which child avoids mother and acts coldly to her

Anxious resistant attachment—a form of insecure attachment where the child remains close to mother and remains distressed despite her attempts to comfort

Language DevelopmentCooing—vowel sounds produced 2–4 monthsBabbling—consonant/vowel sounds between 4 to 6 monthsOne-word stage of language—year old

Comprehension Vocabulary: words that are understood by an infant or child.Production Vocabulary: words that an infant or child understands and can speak.

Two-word stage—2 years old

Gender Role Gender: cultural, social and psychological

meanings that are associatded with masulinity or femininity.

Gender identity: person’s psychological sense of being male or female.

Gender role: behaviors, attitudes, and personality traits that a given culture designate as masculine or feminine.

Children identify themselves and others as male or female around 2.

Piaget’s Theory of Cognitive DevelopmentJean Piaget (1896–1980) Swiss psychologist who became leading theorist in 1930s.These “understandings” are in the form of structures he called schemas.

PiagetSchemas are frameworks that develop to help organize knowledge.Assimilation—process of taking new information or a new experience and fitting it into an already existing schemaAccommodation—process by which existing schemas are changed or new schemas are created in order to fit new information

Example A child believes that "All furry four

legged animals are dogs". The child sees a raccoon (or a cat, squirrel whatever) and the child says, "That's a dog.“ (Assimilation) But his parents tell him it isn't a dog, it's a raccoon. So the child accommodates.

Sensorimotor Stage (birth-2)Information is gained through the senses and motor actions.In this stage child perceives and manipulates but does not reason.Symbols become internalized through language development.Object permanence is acquired.

Object PermanenceThe understanding that objects exist independent of one’s actions or perceptions of them.Before 6 months infants act as if objects removed from sight cease to exist.

Can be surprised by disappearance/reappearance of a face (peek-a-boo).

Preoperational Stage (2-7 years)Emergence of symbolic thought—ability to use words, images, and symbols to represent the world.Centration—tendency to focus, or center, on only one aspect of a situation, usually a perceptive aspect.Egocentrism—Lack of ability to consider events from another person’s point of view.Lack the concept of conservation—understanding that two equal quantities remain equal even though the form or appearance is rearranged.

Concrete Operational Stage (7-12 years)Understanding of mental operations leading to increasingly logical thought.Classification and categorizationLess egocentricInability to reason abstractly or hypothetically—limited to childs experiences

Formal Operational Stage (12-Adulthood)Hypothetical-deductive reasoning

Able to think in abstract terms

Logical thinking

Critique of Piaget’s TheoryUnderestimates infant and children’s cognitive abilitiesUnderestimates the role of the social and cultural environmentOverestimates the degree to which people achieve formal operational thought processes

Vygotsky’s Sociocultural Perspective Vygotsky—children learn from

interactions with other people Zone of proximal development—what

children can accomplish on their own and what they can accomplish with the help of others who are more competent. Tying a shoe

Critical thinking based on dialogue with others who challenge ideas

Physical and Sexual DevelopmentPuberty—stage where an individual reaches sexual maturity and is physically capable of sexual reproductionPrimary sex characteristics—sex organs directly involved in reproductionSecondary sex characteristics—develop during puberty, not directly involved in reproduction, but distinguish male from femaleAdolescent growth spurt—period of accelerated growth during pubertyMenarche—female’s first menstrual period

Early vs. Late MaturationEarly maturation for girls carries greater risks (negative body image, teenage pregnancy, weight gain, embarrassment)

Can be advantageous for boys (popularity), but also carries risks (depression, drug use)

Erikson’s Psychosocial TheoryBiological in belief that there are innate drives to develop social relationships and that these promote survival (Darwinism).Outcome of each stage varies along a continuum from positive to negative.Identity: person’s sense of self, including his or her memories, experiences, and the values and beliefs that guide his or her behavior.

Kohlberg’s Stages of Moral Development

Physical and SocialGenetics and lifestyle combine to determine course of physical changes.

Females- menopause (cessation of menstrual cycle)Males- climacteric (gradual decline in production of sperm– men may remain able to reproduce into 80s and 90s)

Social development involves marriage and transition to parenthood.

Median Age at First Marriage

Changing Structure of American Families and Households

Death and DyingIn general, anxiety about dying tends to decrease in late adulthood.Kubler-Ross stages of dying

Denial Anger Bargain Depression Acceptance

Not universally demonstrated