Human Development Development Parenting styles Cognition DNA Theories of development Conception Genes Developmental theorists Assimilation Genotype Teratogenic effects Threshold effect Phenotype Imprinting Accommodation Gamete Stranger anxiety Germinal stage Zygote Theory theory Embryonic stage Attachment Theory of mind Fetal stage Interaction effect Apgar scale Critical periods Addiction Dizygotic/Monozygotic twins
The sperm and ovum receive only one member of each chromosome pair when cells divide to produce gametes, and thus have only 23 single chromosomes each • Gamete-a reproductive cell, a sperm or ovum that can produce a new individual if it combines with a gamete from the other sex to make a zygote • Zygote- the single cell formed from the fusing of two gametes, a sperm & an ovum • How does conception occur? • Conception occurs when the male gamete (or sperm) penetrates the membrane of the female gamete (the ovum); the gametes fuse and their genetic material combines to form one zygote • Where does the zygote develop? • The amniotic sac is the fluid-filled pouch in which the embryo will live until birth • The amniotic sac acts as both a cushion against the environment and as a temperature regulator
The 23rd pair of chromosomes determines the sex • The chemical on the Y chromosome signals the development of the male organs • The chromosomal make up is XY in the male and XXin the female • In a stressful pregnancy, XY embryos are more likely than XXs to be expelled in a spontaneous abortion, or miscarriage • Within hours, the zygote initiates human development through the process of duplication and division • Implantation begins about 10 days after conception, the organism buries into the placenta for nourishment • Then differentiation begins, this is when cells begin to specialize, taking different forms and reproducing at various rates • At the eight-cell stage, the organism has stem cells it could develop into a body part • The cells on the outer side of the of the mass become the placenta-the organ that will support the life • Certain genes begin to switch on an off during this developmental stage • In some pregnancies, a single zygote splits into two separate identical cells that develop into genetically identical or monozygotic (MZ) twins • MZ twins have the potential for developing the same physical appearance and psychological characteristics, but they are also vulnerable to specific diseases • Dizygotic (DZ) or fraternal twins begin life as separate zygotes, and share no more genes than any other sibling (about 50 percent)
Gestation • The 1st 2 weeks of prenatal development are called the germinal period • The embryonic period begins in the 3rd week as the formless mass becomes a distinct being, which is now referred to as an embryo • A thin line down the middle of the outer layer of cells is the primitive streak, and the structure becomes the neural tube, thenthe brain and spinal column (the central nervous system)
The third week to the eighth week begins the embryonic phase…the developing mass can now be considered an embryo • 5th – 6th week: primitive gonads form • 7th – 8th week: gonads become testes with Y chromosome and the SRY gene • In the 4th week, the cardiovascular system is functioning; the eyes, ears, nose, and mouth start to form • At 5 weeks, the arm and leg buds appear and the primitive heart is now visible • By the end of the 2nd month, the developing organism has all the basic organs and body parts of a human being, and a unisex structure called the indifferent gonad
The fetal period-from the 9th week after conception, the sex organs begin to take shape • By the 12th week, the genitals are fully formed • A sonogram is readable • By the 12th week, the genitals are fully formed • A sonogram is readable
At the end of the 3rd month, the fetus has all its body parts • *22 weeks-signals the age of viability- the ability of the fetus to live outside of the body • During this time, the brain develops new neurons in a process called neurogenesis and new connections between them in a process called synaptogenesis • Weight gain during the final 3 months is 41/2 pounds • The neurological, respiratory, and cardiovascular systems mature dramatically; brain growth is so extensive that the brain’s cortex must fold into layers in order to fit into the skull
Variables that may affect the fetus… • Teratology is the study of birth defects; teratogens include such substance as viruses, drugs, chemicals, stressors, and environmental hazards that can impair developmental and lead to birth defects and even death • The critical periods are times when the body is most susceptible to teratogenic damage • For behavioral teratogens that affect the brain and nervous system, the entire prenatal period is critical • For some teratogens, the threshold effect is imperative; this means that the substance is not harmful until the chemical reaches a certain level • The interaction effect of teratogens occurs when one teratogen intensifies the impact of the other
Zygotes that are formed from abnormal or fragile gametes may not duplicate, divide, or differentiate • * the variable that most often correlates with chromosomal abnormalities is the mother’s age • The most common of the extra-chromosome syndrome is Down Syndrome (trisomy 21) • Persons with Down Syndrome exhibit distinguishing features of the slanted eyes, rounded face, and a thick tongue • the extra chromosome at site 21 also makes them more susceptible to heart defects, slow intellectual development, and by middle age Alzheimer’s disease it’s inherited • *people with this syndrome age faster than other adults
Baby is born! What are reflexes? • Reflexesare involuntary responses to stimuli • What are some examples of reflexes? • Rooting, Babinski, stepping • The infant is born around the 38 week of pregnancy (9 ½ months) • Newborns are born with survival reflexes that prepare them for their new world • Tonic neck reflex • When the baby is laid on its back, baby turns its head and extends arms to same side, helps develop eye/hand coordination • Moro reflex • When baby is dropped or hears a loud noise, baby extends arms and legs and quickly brings them in as if trying to grasp something • Withdrawal reflex • When a soft pinprick is applied to baby, the sole of baby’s foot, baby flexes the leg, helps protect the infant from harmful stimuli
Motor Development First, infants begin to roll over. Next, they sit unsupported, crawl, and finally walk. Experience has little effect on this sequence.
Baby Preferences • The infant is born with an acute auditory sense? Why do you think this is? • Newborns have a preference for human faces, which human face do you think newborns prefer most? • Newborns have a preference for the smell of their mother’s milk • Newborns have a preference for sweet tastes
Cognitive Development Cognition refers to all the mental activities associated with thinking, knowing, remembering, and communicating. Developmental psychologist Jean Piaget believed that children reason differently than adults and that a child’s mind develops in a series of stages. Jean Piaget (1896–1980)
Schemas Piaget felt that the driving force behind our intellectual progression is an unceasing struggle to make sense of our experiences and that to do this maturing brains build schemas. Schemas are concepts or frameworks that organize and interpret information. To use our schemas Piaget proposed that we assimilate new experiences, or interpret them according to our schemas and then adjust or accommodate our schemas accordingly.
Theory-theory is the idea that children attempt to construct theories to explain everything they see and hear • As preschoolers develop informal theories that attempt to answer basic question about mental process-thoughts, emotions, beliefs, motives, and intentions-they acquire a theory of mind • By age 4, young children come to realize that mental phenomena may not reflect reality and that people can deliberately deceived or fooled • Theory of mind is strengthened by a combination of factors, including maturation of the brain’s prefrontal cortex • Schemas- our understanding of the world
Erik Erikson, Psychosocial Development • Erikson maintains that development occurs through a series of basic crises. • Erikson describes the basic crises of infancy and toddlerhood as those of trust v mistrustand autonomy v shame and doubt • In Eriksons’s view, parental guidance and protection are the keys to the child’s gaining a healthy sense of autonomy. • Infants who fail to develop trust or achieve autonomy may become adults who are suspicious and pessimistic or who are burdened by shame.
Gender Identity • Sex is defined by biology • The child learns to identify themselves as male or female…body shape, pregnancy • Gender is defined by the child’s culture • Gender is a shared cultural definition of what it means to be masculine or feminine • Gender roles are cultural expectations about the appropriate behavior for each gender
Freud’s Psycho-Sexual Theory • Freud suggested that children identify with their same-sex parent • Identification provides the foundation for gender identity • Anxiety and a desire for power provides the motivation for identification • Focusing on emotional identification is one way to explain the powerful gender roles that most people accept as part of their self-concept
Attachment • Mary Ainsworth has developed laboratory procedure for measuring the security of attachment • The procedure is called the Strange Situation-infants’ reactions to the comings and going of their mothers and to friendly strangers are monitored • Fully formed fear emerges at about 9 months. One expression of this new emotion is stranger wariness, which emerges between 9 and 14 months; another is separation anxiety, or fear of abandonment, which becomes most obvious at 9 to 14 months. • Approaching and following their caregivers are signs of proximity-seeking behaviors, while holding and cuddling are signs of contact; maintaining these behaviors are signs of attachment
A secure attachment(TypeB)is one in which the infant derives comfort and confidence from the caregiver-this is a type of attachment in which the caregiver acts as a base for exploration • Insecure-avoidant attachment (Type A)-infants who display insecure attachment may engage in little interaction with their mothers and show no apparent distress when they leave • Insecure-resistant/ambivalent attachment(TypeC)- infants show an inconsistent mixture of behavior toward their mothers, such as both resisting and seeking contact • Disorganized attachment (TypeD)- found in the most troubled infants
Contact is a key to attachment • Familiarity is another key to attachment • Critical periods are the optimal periods when certain events must take place to facilitate proper development • Parenting styles will foster attachment in later developmental stages • Parenting styles • Authoritarian, Authoritative,Permissive,Neglectful
According to epigenetic theory, every human characteristic is strongly influenced by each person’s unique genotype • Temperament refers to “constitutionally based” individual differences in emotions, activity, and self-control • Infants are born with distinct temperaments that are genetic in origin and affect their personality • Personality traits are generally considered to be primarily learned; temperamental traits are considered to be primarily genetic • According to the New York Longitudinal Study (NYLS), infants can be described as possessing one of four temperaments: • 1. easy-(40 percent) • 2. slow to warm up-(15 percent) • 3. difficult-(10 percent) • 4. hard to classify-(35 percent)
An important factor in healthy psychosocial development is the goodness of fit between the developing child and the caregiving context • If attachment is not developed between caregiver and infant, severe depression or other serious problems may arise…post partum depression, developmental delays, failure to thrive • Failure to thrive is the diagnosis for an infant who does not grow, develop, or gain weight on schedule
Social Development Stranger anxiety is the fear of strangers that develops at around 8 months. This is the age at which infants form schemas for familiar faces and cannot assimilate a new face.
Adolescence begins with puberty…puberty indicates sexual maturity (only) • Puberty refers to the rapid physical growth and sexual maturation that end childhood, eventually producing a person of adult size and sexual potential • Primary sex characteristic- the reproductive organs and external genitalia • Primary sex characteristics refer to organs involved in conception and pregnancy…vagina, uterus, ovaries, testicles, and penis • Secondary sex characteristics-the non-reproductive traits such as breasts and hips, facial hair and deepened voice in boys
For girls, the sequence of biological changes of puberty is…. • The growth of nipples • First pubic hairs • Height spurt • First menstrual cycle, menarche • Final pubic-hair growth • Full breast development • The first set of publicly visible changes during puberty is the growth spurt…a sudden, uneven increase in the size of almost every body part
Sex hormones • In adolescence, the pituitary glands activate the gonads or the sex glands…the gonadotrophin-releasing hormones causes the gonads to increase production of estrogen and androgens…estrogen for girls and testosterone for boys • The sex hormones affect the body’s shape and functioning, including production of other hormones that regulate stress and immunity…estradiol and testosterone levels may also explain sex differences in psychopathology • The behaviors triggered by hormones are responses to moodiness and lust • Certain behaviors are influenced by biology…aggressiveness, males produce more testosterone • Culture influences the gender roles, thus influencing how those behaviors manifest • Culture/biology influences sexual behaviors
Age of puberty varies among ethnic groups, most likely because of genes…African American females reach puberty earlier than others • For both sexes, malnutrition delays puberty…the secular trend indicates that it causes puberty to start earlier and make people shorter, and has stopped in developed nations • Stress affects puberty hormones by increasing production • Cohorts are also influencing for early maturing boys…delinquency training • Early maturing girls tend to experience depression, have more boyfriends, lower self-esteem, and poorer body image • Early maturing males engage in delinquent behavior, start drinking earlier, engage in sexual behaviors earlier, and are more aggressive than later maturing boys • Later maturing boys also engage in delinquent behavior which may be due to depression and self-esteem issues, afraid of sex, and more anxious • Development continues into the emerging adulthood period…cognitive, psychosocial
Emerging Adulthood Emerging adulthood spans from the late-teens to the mid-twenties. During this time, young adults may live with their parents and attend college or work. On average, emerging adults marry in their mid-twenties.
3 Basic Levels of Moral Thinking Preconventional Morality: Before age 9, children show morality to avoid punishment or gain reward. Conventional Morality: By early adolescence, social rules and laws are upheld for their own sake. Postconventional Morality: Affirms people’s agreed-upon rights or follows personally perceived ethical principles.
Kohlberg’s, Moral development • Level I (preconventional) • Stage I-Obedience and Punishment orientation (similar to Piaget 1st stage) –It’s wrong to steal because you’ll get punished, rewards from the outside world • Stage 2-Individualism and Exchange-different individuals have different viewpoints –What’s in it for me? (self-interests), punishments from the external world • Level II (conventional) • Stage 3-Interpersonal accord and conformity- social norms-people should live up to others’ expectations of the family and community and behave in good ways-he loves his wife; no husband should let his wife die (good boy/g) adolescents value loyalty to others as a basis for moral judgments • Stage 4-Authority and Maintaining Social Order-obeying the law, respecting authority-what would happen if we all started stealing? Cannot condone theft social order, justice and duty are important in making decisions
Level III (Post conventional) • Stage 5-Social Contract and Individual Rights-it is a human’s basic right to live and this supersedes the law (moralistic) the importance of individual rights are the basis for moral decisions • Stage 6-Universal Principles-there should not be a law that protects some and hurts others( uphold social contracts and laws that promote a good society) universal ethical principles, complete selflessness
Marica’s Stages of Identity Development • Identity-diffusion the individual does not have firm commitments regarding the issues in question and is not making progress toward them • Foreclosure-the individual has not engaged in any identity experimentation and has not established an identity based on the choices or values of others
Moratorium-the individual is exploring various choices but has not yet made a clear commitment to any of them • Identity achievement-the individual has attained a coherent committed identity based on personal decisions • During this time of identity development, adolescents rely less on parents’ views and defer instead to peers
Cognitive changes in late adulthood • As neurogenesis slows down, the memory functions decrease • Crystalized intelligence, accumulated knowledge may remain stable, but fluid intelligence, intelligence for reasoning, thinking quickly and abstractly declines • Older adults may find it necessary to resort to memory cues…
Aging and Memory • Recognition memory does not decline with age, and material that is meaningful is recalled better than meaningless material. • Some older adults suffer from biologically based cognitive impairments in which the brain is so adversely affected by aging that it becomes very difficult for the person to continue to function effectively.
Death and Dying The “normal” range of reactions or grief stages after the death of a loved one varies widely. Grief is more severe if death occurs unexpectedly. People who view their lives with a sense of integrity (in Erikson’s terms) see life as meaningful and worthwhile. Life satisfaction before, during the year of, and after a spouse’s death