HUMAN DEVELOPMENT
HUMAN DEVELOPMENT
Chapter 8
PSYCHOLOGY DEBORAH M. LICHT MISTY G. HULL COCO BALLANTYNE
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Voices
GIRL WITH POTENTIAL
Ericka Harley was 16 years old and starting her junior year of high school when she found out she was pregnant.
Her mother, Joan, was disappointed to discover that her daughter, an honor-roll student, would soon be a mom; she had hoped Ericka might attend college and enjoy a successful career.
Would Ericka ever make it to college?
The Study of Human Development (part 1)
DEVELOPMENTAL PSYCHOLOGY
Refers to field of psychology that examines physical, cognitive, and socioemotional change
The Study of Human Development (part 2)
Socioemotional development
Refers to social behaviors, emotions, and changes experienced in relationships, feelings, and overall disposition
Physical development
Involves maturation wherein the body follows a universal, biologically driven progression in a generally predictable pattern
Cognitive development
Includes changes in memory, problem solving, decision making, language, and intelligence that tend to follow a universal course early in life and considerable variability with age
The Study of Human Development (part 3)
BIOPSYCHOSOCIAL PERSPECTIVE
Recognizes contributions and interplay of biological, psychological, and social forces facing human development
THREE MAJOR THEMES OR DEBATES
Stages or continuity
Hereditary and environmental influences
Stability and change
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The Study of Human Development (part 4)
RESEARCH METHODS USED TO STUDY DEVELOPMENTAL PROCESSES
Cross-sectional method
Examines people of different ages at a single point in time
Longitudinal method
Examines one sample of people over a period of time to determine age-related changes
Cross-sequential method
Examines groups of people of different ages, following them across time
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Genetics, Conception, and Prenatal Development (part 1)
CHROMOSOMES AND GENES
Chromosomes
Inherited threadlike structures composed of deoxyribonucleic acid (DNA)
Deoxyribonucleic acid (DNA)
Molecule that provides the instructions for the development and production of cells
Gene
Specified segment of a DNA molecule
Genetics, Conception, and Prenatal Development (part 2)
CHROMOSOMES, DNA, AND GENES
Every cell in your body, except red blood cells and sex cells (sperm or egg), contains a full set of 23 chromosome pairs like those shown here.
These 23 chromosome pairs contain the full blueprint for you as a complete, unique person. The primary component of each chromosome is a single, tightly wound molecule of DNA. Within that DNA are around 21,000 genes (Pennisi, 2012, September 5), each determining specific traits such as hair texture. Note the sex chromosomes (X and Y) on the lower right, indicating that the sex is male. Photo: CNRI/Science Source.
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Genetics, Conception, and Prenatal Development (part 3)
CHROMOSOMES AND GENES
How exactly did you get your genes from your biological parents?
Genes are found in chromosomes.
Chromosomes inherited from biological parents.
Sperm and egg both contain 23 chromosomes = 23 pairs.
Twenty-third chromosome pair determines genetic sex.
XX = female; XY = male
Genetics, Conception, and Prenatal Development (part 4)
Researchers with the Human Genome Project have decoded the entire human genome, which contains about 21,000 DNA segments known as genes (Pennisi, 2012, September 5).
Genes are the blueprints for proteins that endow you with a unique set of traits, including eye color, hair texture, and—to a certain extent—psychological characteristics.
The colored lights are an artistic representation of the human genome, the complete set of DNA found in most cells in the body.
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Genetics, Conception, and Prenatal Development (part 5)
CHROMOSOMES AND GENES
Genotype
Includes an individual’s complete collection of genes
Does not change in response to the environment but interacts with it—outcome is not predetermined
Phenotype
Refers to the observable characteristics of an individual that are the result of this interaction
Includes unique physical, psychological, and behavioral characteristics
Epigenetics
Examines the process involved in the development of phenotypes
Genetics, Conception, and Prenatal Development (part 6)
CHROMOSOMES AND GENES
The dominant gene governs the expression of inherited characteristics.
The recessive gene cannot overcome the influence of the dominant gene.
The “widow’s peak,” or V-shaped hairline, is thought to be determined by the presence of a single, dominant gene (Chiras, 2015). The man on the left must have at least one dominant widow’s peak gene, while the man on the right has two recessive straight hairline genes.
Genetics, Conception, and Prenatal Development (part 7)
FROM ZYGOTE TO EMBRYO TO FETUS
Zygote
Single cell formed by the union of a sperm cell and an egg
Travels down the fallopian tube while dividing into more cells
Multiples
Monozygotic twins develop from one egg inseminated at conception.
Dizygotic twins occur when two eggs are inseminated by two different sperm.
Genetics, Conception, and Prenatal Development (part 8)
Germinal period (conception to end of 2nd week)
Implanting in uterine wall; rapid growth
Embryo period (3rd to 8th week)
Cell differentiation; formation of major organs and systems begin
Heart begins to beat; spinal cord and intestinal systems develop by end of period
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Genetics, Conception, and Prenatal Development (part 9)
Fetal period (2nd month to birth)
Rapid weight gain; clear sleep-wake cycles; all organs, systems, and structures fully developed at birth
Brain weight one quarter of adult size
Prenatal Development and Periods of Critical Growth
Genetics, Conception, and Prenatal Development (part 10)
Teratogens
Embryos are not protected from all environmental dangers.
Teratogens can damage a zygote, embryo, or fetus.
Damage depends on the agent, timing, and duration of exposure.
Genetics, Conception, and Prenatal Development (part 11)
CAN YOU IDENTIFY THE POTENTIAL EFFECTS OF TERATOGENS IN EACH OF THESE CATEGORIES?
Drugs
Environmental factors
Infections
Maternal disease
From conception until birth, the developing human is nestled deep inside a woman’s body, but it remains vulnerable to threats from the outside. See Table 8.1 for some common teratogens and their effects.
See Table 8.1 for additional information about the dangers of teratogens. From conception until birth, the developing human is nestled deep inside a woman’s body, but it remains vulnerable to threats from the outside. Listed here are some common teratogens and their effects. Information from Brent (2004)
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Genetics, Conception, and Prenatal Development (part 12)
THE FETAL PERIOD
Between 2 months and birth (fetus)
Average birth weight around 7 pounds by North American standards
Sleep-wake cycles demonstrated
FETAL ALCOHOL SYNDROME (FAS)
Delays in development that result from moderate to heavy alcohol use during pregnancy
Symptoms may include physical growth delays, learning disabilities, and problems with anxiety, attention, and impulse regulation.
Infancy and Child Development (part 1)
NEWBORN GROWTH AND DEVELOPMENT
Newborn reflexes
Automatic responses to stimuli
Some necessary for survival; other no obvious purpose
Examples
Rooting, sucking, grasping, Babinski, stepping, Moro
See Table 8.2 for additional information about newborn reflexes.
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Infancy and Child Development (part 2)
NEWBORN GROWTH AND DEVELOPMENT
Newborn senses
Prefer human faces as opposed to geometric shapes
Discriminate mother’s voice shortly after birth
Distinguish smell of mother’s breast milk
Prefer sweet tastes, react to sour tastes, notice differences in breast milk taste
React to sense of touch
Respond to pain
Have blurred vision for several months
Infancy and Child Development (part 3)
Infancy and Child Development (part 4)
THE GROWING BRAIN
Synaptic pruning
Increase in neural connections is not uniform in brain
Unused synaptic connections eliminated
Decrease in neural connection by 40–50% by puberty
Rosenzweig’s rats
Rosenzweig and colleagues demonstrated how environment influences animal brain development.
Rats with an enriched environment experienced greater increases in brain weight and synaptic connections.
Infancy and Child Development (part 5)
THE LANGUAGE EXPLOSION
Behaviorism and language
Proposes that all behavior—including language—is learned through associations, reinforcers, and observations
Suggests language is learned through positive attention to correct behavior and unpleasant attention to incorrect behavior
Infancy and Child Development (part 6)
THE LANGUAGE EXPLOSION (LAD)
Language acquisition device
Provides universal, innate mechanism for language learning (Chomsky)
Infant-directed speech (IDS)
Used by caregivers worldwide and stimulates infant attention to socially appropriate partners
Infancy and Child Development (part 7)
THE LANGUAGE EXPLOSION
Language in the environment
The amount of language in the home correlates with SES.
The quality of speech input is also critical to language development.
A lag in reading, math, and academic achievement in general is found in children of lower SES status who are beginning school.
Infancy and Child Development (part 8)
THE LANGUAGE EXPLOSION
Sequence of acquisition
Cooing
Babbling
Telegraphic speech
NATURE AND NURTURE
GENIE THE “FERAL CHILD”
In 1970, a social worker in Arcadia, California, discovered 13-year-old “Genie.” Between the ages of 20 months and 13 years, Genie suffered abuse, deprivation, and neglect. She was deprived of physical activity, sensory stimulation, and affection.
Efforts to build Genie’s vocabulary had mixed success. She learned basic syntax principles and eventually spoke meaningful sentences. There were, however, certain linguistic skills that could not be mastered.
Why couldn’t Genie master these certain linguistic skills? What implications does this have for all child language development?
Infancy and Child Development (part 9)
PIAGET AND COGNITIVE DEVELOPMENT
One of…
