PSY 001 Lecture Notes - Lecture 14: Prenatal Development, Y Chromosome, Human Reproduction
12 Jun 2018
School
Department
Course
Professor
Psych – Human Development
Jadzia Wray
Developmental psychology
- Includes the scientific study of biological, cognitive, social, and personality development
throughout the lifespan
- Involves the nature-versus-nurture question
- Do our traits and behaviors result from heredity (nature) or the environment (nurture)?
Life Span
- Table 7.1 Dividing the Life Span Into Developmental Stages Stage
o Prenatal: Conception to birth
o Infancy: Birth to 2years
o Childhood: 2 to 12years
o Adolescence: 12 to 18years
o Young adulthood: 18 to 40years
o Middle adulthood: 40 to 65years
o Late adulthood: 65 years and over
Prenatal Development
- Human conception
o Begins when a sperm penetrates the membrane of an ovum
- When the two combine
o Complete set of genetic instructions is formed: half from the father and half from the
mother
- Every cell of a normal human
o Has 23 pairs of chromosomes
o Includes one of each pair coming from the mother and one from the father.
- Zygote
o Fertilized egg that is formed from the union of the sperm and egg cells in human
reproduction
- Gene
o Basic unit of genetic instruction
- Chromosomes
o Molecules of DNA that hold the genetic instructions for every cell in the body
- Molecules
o Consist of short segments of chromosomes
o Hold the genetic instructions for every cell in the body
- Sex determination
o 23rd pair of chromosomes that determines person's sex
▪ Female = two X-shaped chromosomes (XX)
▪ Male = one X-shaped chromosome and one smaller Y-shaped chromosome (XY)
▪ Y chromosome = Leads to development of a male
- Identical (monozygotic) twins
o Occurs when growing cluster of duplicated cells breaks apart early in development,
resulting in two clusters with identical genes
o Clusters become identical twins because they come from the same zygote.
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- Fraternal (dizygotic) twins
o Originate from fertilization of two eggs at about the same time
o Consequently, fraternal twins, as well as any two children of the same parents, may vary
greatly in appearance.
- Influences
o Zygote's genetic code (nature)
o Environment (nurture)
▪ Teratogens – chemicals or stressors that alter the a’s deelopet i a ad
way - alcohol
▪ Diseases – e areful that pregat oe do’t get sik. Pregat oe do’t
go to aer patiets’ / the patiets hae lo iuities ad pik up ore
disease
▪ Physical conditions
▪ Drug use – anything the mom gets, goes to the baby. Alcohol alters
neurotransmitters and it could damage the baby greatly since they are already
forming
How we develop during infancy: motor development
- A newborn is born with several motor reflexes
o Survival: Sucking; Rooting
o Remain after birth: Breathing
o Disappear: Babinski (touch their toes and it curls); grasping
- Orderly sequence of motor development
o Prop up and support body → crawl →stand with support → stand without support →
walk
Sensory – Perceptual Development
- Habituation
o Decrease in the physiological responding to a stimulus once it becomes familiar
o Infants tend to look longer at novel stimuli. Once the baby has figured out the stimulus,
they stop looking at it
o Infants also intensify their sucking of a pacifier when confronted with a novel stimulus
- Processing structural relationships between individual facial features
o Newborns are sensitive to configurable information in faces (Leo and Simion).
o If the mom looks mad but the baby is happy, once the baby notices the mother is not
happy, the baby will be very dysregulated and confused.
- Vision
o Birth: Least-developed sense
o Newborn: Visual acuity is estimated to be about 20/400 to 20/800.
o Two to three months: Color vision develops.
o Within first year of life: Visual acuity reaches 20/20.
- Infants' preference for visual complexity
o Such stimulation is necessary for proper development of the visual pathways and cortex
during infancy.
o Cartoons are colorful and exciting so that attracts children, children are like sponges
find more resources at oneclass.com
find more resources at oneclass.com
- Hearing
o Before birth: Ability appears to develop in the womb.
o Newborn: Hearing is more fully developed than vision.
▪ Can distinguish their mother's voice from those of others
o By 6 months: Infant hearing is comparable to that of an adult.
- Speech perception
o Infants can detect all phonemes with or without exposure to them.
▪ We do have some skills to help us learn to detect language
o By 12 months, infants can no longer detect nonnative speech sounds.
- Sensory
o At birth: Senses of smell, taste, and touch are also fairly well developed.
o Infants: Can differentiate the smell of their mother from those of other people
- Perceptual
o Very young infants: May have an innate conceptual understanding of object movement
- Brain
o Contains about 100 billion neurons at birth
o Immature; neural networks incomplete
- Use it or lose it
o During infancy, networks of neurons that are used become stronger, and those that are
not disappear.
o Without visual experiences, the visual pathways do not develop, and vision will be
permanently lost.
Visual Cliff
- Gibson and Walk (1960)
o Used visual cliff apparatus to demonstrated depth perception develops rather quickly
o Young infants would not crawl onto apparent steep drop-off.
- Adolph and colleagues (2014)
o Found locomotor learning experience influenced depth perception
o With increased mobility, locomotor experience leads to fear of heights.
o Not developed without exposure to human speech
Piaget’s Theor of Cogitie Deelopet
- Piaget's methodology
o Conducted loosely structured interviews
o Posed problems for children to solve; observed and questioned responses
o Was particularly interested in children's error
o Assumed that a child is an active seeker of knowledge
- Schemas
o Organized units of knowledge about objects, events, and actions
o Cognitive adaptation involves two processes:
▪ Assimilation
▪ Accommodation
find more resources at oneclass.com
find more resources at oneclass.com
Document Summary
Includes the scientific study of biological, cognitive, social, and personality development throughout the lifespan. Table 7. 1 dividing the life span into developmental stages stage: prenatal: conception to birth. Childhood: 2 to 12years: adolescence: 12 to 18years, young adulthood: 18 to 40years, middle adulthood: 40 to 65years, late adulthood: 65 years and over. Human conception: begins when a sperm penetrates the membrane of an ovum. When the two combine: complete set of genetic instructions is formed: half from the father and half from the mother. Every cell of a normal human: has 23 pairs of chromosomes. Includes one of each pair coming from the mother and one from the father. Zygote: fertilized egg that is formed from the union of the sperm and egg cells in human reproduction. Gene: basic unit of genetic instruction. Chromosomes: molecules of dna that hold the genetic instructions for every cell in the body.
