HDFS 201 continued PDF

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The science of human development • Seeks to understand how and why people, all kinds of people, everywhere, of every age, change over time Understanding how and why people develop as they do • Developmental scientists are concerned with trying to discover the process of development and the reasons for those procedures • Developmental science is an actual empirical science. it relies on theories, data, analysis, critical thinking, and south methodology Researchers use the scientific method to conduct studies • The influences of nature and nurture • Nature • General term for the traits,capacities, and limitations that each individual inherits genetically from his or her parents at the moment of conception • Nurture • General term for all of the environmental influences that affect development after an individual is conceived (eg. health and diet, family, school, community, society) Is violence learned? Genetic? - Both • Epigenetic's • Study of the many ways environment alters genetic expression, beginning with methylation at conception and continuing lifelong • Differential susceptibility • Sensitivity to any particular experience divers from one person to another because of the particular genes each person has inherited, or what happened to that person years earlier The how and why people develop as they do also includes identifying and understanding • Critical periods for development - each critical period is a time when certain things must occur for normal development Sensitive periods for development - the time when a particular development occurs more • easily. Window of opportunity The Lifespan Perspective • An approach to the study of human development that takes into account all phases of life Five characteristics of the lifespan perspective 1. Development is multidirectional - over time, human characteristics change in every direction 2. Development is multi contextual - Ecological systems approach - the view that in the study of human development, the person should be considered in all the contexts and interactions that constitute a life 3. Development is multicultural • Culture - the shared system of beliefs, conventions, norms, behaviors, expectations, and symbolic representations that persist over time and prescribe the social rules of conduct • Ethnical group - people whose ancestors were born in the same region and who often share a language, culture, and religion • Race - a group of people who are regarded by themselves or others as distant from other groups on the basis of appearance 4. Development is multidisciplinary

• Studying development incorporated theory and research form psychology, education, sociology, social work medicine, etc. 5. Development is plastic (malleable) Replication - Repetition of a study using different participants Scientific observation • requires the researcher to record behavior systematically and objectively Developmental Theories Developmental theories are based on a group of ideas,a assumptions, and generalization that interpret and illuminate the thousands of observations that have been made about human growth. • Theories are not guesses or facts • Theories organize observations in a coherent story, but the are not laws Developmental theories: a framework for understanding how and why people change as they grow older Psychoanalytic theory • A theory of human development that holds that irrational, unconscious drives and motives, often originating in childhood underlie human behavior • Originated with Sigmund Freud According to Freud, the personality is made up of three parts • Id: largest part of the ind and source of basic biological desires • Superego: conscious part of the mind that conforms to societal expectations • Ego: conscious, rational part of the mind that negotiates between the id and the superego Behaviorism • The study of observable behavior, and the theory (learning theory) explaining the acquisition of habits and competencies Cognitive Theory • How does thinking change over time? Sociocultural theory • Development results from the dynamic interaction of each person with the surrounding social and cultural forces The Genetic Code • Chromosome: One of the 46 molecules of DNA that virtually each cell of the human body contains and that, together, contain all the genes. Other species have more or less chromosomes. • Deoxyribonucleic acid (DNA): The chemical composition of the molecules that contain genes. • Gene: the basic unit for the transmission of heredity • Gamete: a reproductive cell (a sperm or ovum)

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22 or 23 pairs of chromosomes are called autosomes 23rd pair is made up of sex chromosomes All ovum bear an X chromosome Sperm can bear either an X or Y chromosome

• Genotype: All of an individual’s genetic information, including expressed and non-expressed traits • Most traits are: • Polygenic - multiple genes influencing wait the trait is • Multifactorial Phenotype: includes expressed traits only (physical traits) • influences by genes and environment • Gene interaction may • be an additive • follow a dominant-recessive pattern • be X-linked Additive Heredity • Additive genes • Genes that work tougher to add something to some aspect of the phenotype • Effects of additive genes add up to make the phenotype • Example: Height is affected by the contributions of about 100 genes Dominant-Recessive Heredity • Dominant gene is far more influential that the recessive gene (nonadditive) • Dominant gene can completely control the phenotype with no noticeable effect of recessive gene • Effect of recessive genes can sometimes be noticed • Carrier: Person whose genotype includes a gene that is not expressed in the phenotype • Unexpressed gene occurs in half of the carrier’s gametes and is passed on to half of the carrier’s offspring Mother-to-son • X-linked • Special case of dominant-recessive pattern • Gene carried on the X chromosome Chromosomal Abnormalities • Chromosomal abnormalities occur when two chromosomes don't match up exactly as they should at conception • Ideally, chromosomes should come in pairs, but occasionally one in the air is missing or damages, or there is an extra

Down Syndrome/ Trisomy 21 • Person as 47 instead of 46 chromes • Causes intellectual disability, speech problems, and slow motor development • Distant physical characteristics: • flat face • short stature • stocky build • protruding tongue • almond shape eyes • distinctive line across palm of hands Klinefelter Syndrome • Males have an extra X chromosome • Causes learning disabilities, ADHD, depression, and infertility • Physical characteristics • small testes/penis • very little body hair • enlarged breast • tall stature • abnormal body proportions Turner Syndrome • Females missing part or all of an X chromosome • Causes difficulties with math, sense of direction, social skills Prenatal Development Basic Concepts • Types of change during prenatal development • Kind, number, position, size, and shape • Kind - creation of multiple types of structures (heart, brain, bone, etc) • Number - changing numbers of cells • Position - orientation of things (heart grows on top first) • Size - simple growth • Shape - development of form Major phases of prenatal development • Germinal Period (conception -> implantation, first 2 weeks) • Embryonic Period (3-8 weeks from conception) • Fetal Period (9-28 weeks from conception) • The Period of the Embryo • Third Week • Gastrulation: Embryonic disc converts into 3 layers • ectoderm • endoderm • mesoderm • Neurulation: Brain development • Fourth to Eighth Weeks • Folding (ventral and lateral) established body form • Heart begin to beat at beginning of 4th week • All major organs and systems form from 3 layers

• Brain has three vesicles • Most critical period of prenatal development The Period of the Fetus: 9-16 Weeks • Head is 1/2 of entire length; upper and lower limbs lengthen • Beginning of spontaneous movements • By 12th week, external genitalia are formed • At 3 months, fetus weighs about 3 ounces and is 3 inches long • Urine production and excretion begins • Ossification of skeleton begins • By 16th week, ovaries formed in females • Growth is extreme The Period of the Fetus: 17-22 Weeks • Growth rate slows • First detection of movements by mother • Vernix caseosa and lanugo cover skin • Brown fat forms • Weight at 22 weeks = approx. 600g (1.3 lbs) The Period of the Fetus: 23-28 Weeks • Surfactant secreted by lungs at 24 weeks • Viability (22-25 weeks) • By 26 weeks, lungs capable of breathing air, increased chance of survival if born • Increase in size and weight, adding fat Risk Reduction • Teratogens (Harmful Substance): Any environmental or behavioral agent that can harm a fetus, including • Infectious diseases (Rubella, HIV) • Toxins (prescription, OTC, and illegal drugs) • Maternal conditions (malnutrition, stress) • How much damage a teratogen does to an unborn child depends on several factors: • How much of the teratogen the unborn child is exposed to and for how long • Genes • The presence of incense of additional negative factors • Gestational age of the fetus at the time of exposure Birth • Labor typically begins when the fetal brain signals the release of hormones to trigger the contraction of a mother’s uterine muscles • Labor has three stages: • Dilation and effacement of the cervix • Delivery of the baby • Delivery of the placenta

Caesarian Births (C-sections) • The fetus is removed through incisions in the mother’s abdomen and uterus • Common reasons for a C-section include • Baby is in distress • Position of the baby • Pushing stage is taking too long • Mother has active herpes simplex 2 • Previous C-section delivery The Newborn • Apgar scale: A quick assessment of a newborn’s health, given twice (at one minute and five minutes after birth) Low birth weight: less than 5.5 lbs • Very Low birth weight: less than 3 lbs 5 ounces • Extremely low birth weight: less than 2 lbs 3 ounces • Preterm: Child is born more than 3 weeks early • Small for gestational age: Child is smaller than typical given their gestational age (babies with • fetal alcohol syndrome) The Newborn • Reflex: An unlearned, involuntary action or movement in response to a stimulus How long do infants sleep? • All kids sleep fewer hours per 24 hours as they grow, and the range of hours of sleep seems to become less over time • Important factors • WHEN they sleep • Americans tends to place high importance on getting children to sleep through the night, as young as possible • convenience • allows adult to sleep • child care schedules Not the case in all cultures • WHERE they sleep • There is a great variation in terms of where children should sleep • Independent sleeping • • encourages independence and autonomy • can be beneficial to the parents’ relationship • Co-sleeping • promotes breastfeeding • promotes feeling of security/bonding • children fall back asleep faster • HOW they go to sleep/stay asleep • Variation in terms of beliefs about how children should fall asleep • Some believe that infants should be rocked, held, or fed until they fall asleep • Others believe infants should be put down awake so they learn to fall asleep alone

Brain development • Transient exuberance: the great but temporary increase in the number of dendrites that occurs in the infants brain Necessary and Possible Experiences • Experience related aspects of brain function • Experience-expectant: requires basic common experiences for normal development to occur • Experience-dependent: particular experiences that impact brain development, but are not necessary for brain function...