Developmental Psychology 307 1 1 22 2008 Research Strategies z Descriptive studies z Experimental 1 22 2008 Developmental Psychology Lecture1 studies 2 1 Correlational studies New York Times July 1999 3 1 22 2008 Developmental Research Designs z Cross sectional Observes people of different ages or cohorts at one point in time z Longitudinal Observes people of one cohort repeatedly over time z Sequential Combines cross sectional and longitudinal approaches by observing different cohorts repeatedly over time 1 22 2008 Developmental Psychology Lecture1 4 2 Nature Nurture Direction of Effects z z z z Bias in much developmental literature is to view child s behavior as a function of the environment Equally important to recognize that a child also affects the environment Reanalyze a correlational study of adultchild interaction Consider the child s behavior as the independent variable rather than the dependent variable 5 1 22 2008 Example Bell Ainsworth 1972 z z z Documented relationship between maternal responsiveness and infant crying Mothers who were responsive to infants early in life had babies who cried less at a later time in comparison to unresponsive mothers Conclusion Maternal responsiveness affected infant crying 1 22 2008 Developmental Psychology Lecture1 6 3 But Perhaps babies who are difficult to sooth may create mothers who respond to them more slowly z Beware the correlational conclusion z 7 1 22 2008 Three Stages of Prenatal Development z Zygotic period from conception to 2 weeks Embryonic period from 3rd to 8th week z Fetal period from 9th week on z 1 22 2008 Developmental Psychology Lecture1 8 4 Mitosis Body Cells 1 22 2008 9 Meiosis Germ Cells 1 22 2008 Developmental Psychology Lecture1 10 5 1 22 2008 11 1 22 2008 12 Developmental Psychology Lecture1 6 13 1 22 2008 Genetic Problems z Other abnormalities of sex chromosomes Color blindness 8 males in 100 Hemophilia Degeneration of optic nerve Certain types of deafness Night blindness z Autosomal abnormalities 1 22 2008 Developmental Psychology Lecture1 14 7 Stages of Prenatal Period z Zygotic period z Embryonic period z Fetal period 1 22 2008 15 1 22 2008 16 Developmental Psychology Lecture1 8 Zygotic Period z Conception to time blastocyst implants in uterine wall Rapid multiplication of cells Cells begin to differentiate Ectoderm will become skin hair sensory organs nervous system Endoderm will become digestive and respiratory system Mesoderm third layer emerges a bit later will become circulatory and skeletal muscular system Other parts of blastocyst develop into placenta 1 22 2008 17 1 22 2008 18 Developmental Psychology Lecture1 9 Embryonic Period z Third to eighth week Most important stage in terms of differentiation of organs limbs and physiological systems By end all organs have been differentiated although not fully developed Critical period for many aspects of physical development Drugs and other teratogens have greater impact on development now than at any other time As many as one half of all embryos are spontaneously aborted during this period 1 22 2008 19 1 22 2008 20 Developmental Psychology Lecture1 10 21 1 22 2008 By end of embryonic period z z z z z z Embryo is one inch long recognizably human Head makes up 1 3 to of embryo s length Large eyes visible tongue and teeth buds can be seen Legs and arms with distinct toes and fingers are recognizable Stomach produces digestive juices kidneys filter blood from second week on Respiratory system is least developed will not be able to support life until six months after conception 1 22 2008 Developmental Psychology Lecture1 22 11 Fetal Period z Begins 2 to 3 months after conception when organogenesis is complete Bone cells begin to develop Organogenesis is largely over so chance of gross structural malformations due to teratogens decreases At beginning of period organs just vaguely resemble their future structure and function Connections between different organs begin to develop which means the fetus does NOT simply grow bigger 1 22 2008 23 1 22 2008 24 Developmental Psychology Lecture1 12 Final Point re Fetal Period z z z z From third month fetus begins to swallow and urinate various reflexes begin to emerge From six months 28 weeks fetus is capable of breathing and crying and is viable all sensory system are functional During last three months rapid growth slow drastically Fat pad begins to form under skin in eighth month 1 22 2008 25 Prenatal Environmental Influences Teratogens z Other maternal factors z Paternal influences z 1 22 2008 Developmental Psychology Lecture1 26 13 Teratogens Prescription non prescription drugs z Illegal drugs z Cigarette smoking z Alcohol z Other z 27 1 22 2008 Teratogens z z z z Larger doses over time usually have a more serious effect Genetic makeup of mother and developing organism may make them more less susceptible Presence of risk factors poor nutrition lack of medical care can worsen the effect of a single harmful agent Effects vary depending on age of organism at time of exposure 1 22 2008 Developmental Psychology Lecture1 28 14 Prescription Non Prescription Drugs Just about any drug taken by mother can enter the embryo fetal bloodstream through the placenta z Example Thalodimide z 1 22 2008 29 Illegal Drugs Babies born to mothers who use cocaine heroin or methadone are at risk for a wide variety of problems z Prematurity low birth weight physical defects infant death z Low attentiveness to environment low responsiveness to stimuli z Consequences may be long term z 1 22 2008 Developmental Psychology Lecture1 30 15 Cigarette Smoking z z z z Best known effect is low birth weight also associated with prematurity miscarriage and infant death Newborns are unresponsive to environment and show increased muscle tension How Nicotine causes placenta to gwow abnormally affecting fetal nutrition Smoking creates increase of carbon monoxide in bloodstream decreases supply of oxygen to fetus 31 1 22 2008 Alcohol z z z z z Fetal Alcohol Syndrome FAS Mental retardation slow physical growth facial abnormalities Fetal Alcohol Effects FAE some but not all of above abnormalities How Alcohol interferes with formation of brain and nervous system Metabolism of alcohol in mother s body draws oxygen from developing fetus 1 22 2008 Developmental Psychology Lecture1 32 16 33 1 22 2008 Other Hormones Radiation Environmental pollution Rubella AIDS Genital Herpes Chicken Pox Mumps etc 1 22 2008 Developmental Psychology Lecture1 34 17
View Full Document
Unlocking...