devpsy p3

• Evolutionary perspective

  • Natural selection is the process by which those individuals of a species that are best adapted survive and reproduce
  • Darwin proposed that natural selection fuels evolution
  • Those that survive and reproduce pass on their characteristics to the next generation
  • Survivors are better adapted than those that did not survive
• Adaptive behaviors


  Behaviors that promote an organism's survival in the natural habitat
• Attachment between a caregiver and a baby

  • Ensures the infant's closeness to a caregiver for feeding and protection from danger, thus increasing the infant's chance of survival
• Evolutionary psychology


  • Emphasizes the importance of adaptation, reproduction, and "survival of the fittest" in shaping behavior
• Evolution gave us biological propensities but it does not dictate behavior. People have used their biological capacities to produce diverse cultures – aggressive and peace-loving, egalitarian and autocratic
• Biology allows a broad range of cultural possibilities
• Fertilization


  The first cell of a new human being forms when an egg cell (from the mother) combines with a sperm cell (from the father)
• Cell division


  1. A complete copy of the genetic information is passed on to the two new ("daughter") cells

  2. As the growing baby develops in the womb, cells continue dividing, leading to the formation of various types of cells, tissues and organs
• Heredityor inherited genes


  Genes being passed on from parents to children
• DNA


  • Deoxyribonucleic acid, the strands of which look like a twisted ladder, known as a double helix
  • Each step of this ladder is made up of two bases: adenine (A), thymine (T), guanine (G), and cytosine (C)

  
• Gene


  The sequence of genetic information that contains the building instructions for a specific protein
• Chromosomes


  Strands of DNA in the cell nucleus, which come in pairs

  
• Human chromosomes


  • 22 pairs of autosomes
  • 1 pair of sex chromosomes (XX for women, XY for men)

  
• What we look like and how our body functions is determined by a combination of our genes, our lifestyle and our environment
• Alleles


  The different versions of the same gene, one inherited from the father and one from the mother

  
• Dominant and recessive


  • When one allele of a gene is "stronger" and determines the expressed trait, overriding the other allele (dominant)
  • The weaker allele is referred to as "recessive"
• Inheriting one gene from the mother and one from the father has advantages, such as reducing the severity of diseases caused by recessive alleles and creating new gene combinations
• Genetic disorders


  Caused by mutations in one gene (monogenic), multiple genes (multifactorial), a combination of gene mutations and environmental factors, or damage to chromosomes
• Genetic disorders


  • Down syndrome (extra copy of chromosome 21)
  • Sex-linked conditions like Klinefelter syndrome, fragile X syndrome, Turner syndrome, and XYY syndrome
  • Gene-linked abnormalities involving harmful or absent genes

  
• Ultrasound is used in prenatal development
• Genetic disorders can be caused by a mutation in one gene (monogenic disorder), by mutations in multiple genes (multifactorial inheritance disorder), by a combination of gene mutations and environmental factors, or by damage to chromosomes (changes in the number or structure of entire chromosomes, the structures that carry genes)
• Chromosomal abnormalities


  • Down syndrome (caused by an extra copy of chromosome 21)
  • Klinefelter syndrome
  • Fragile X syndrome
  • Turner syndrome
  • XYY syndrome

  
• Gene-linked abnormalities involve harmful or absent genes
• Prenatal diagnostic tests


  • Ultrasound sonography
  • Fetal MRI
  • Chorionic villus sampling
  • Amniocentesis
  • Maternal blood screening

  
• Determination of the sex of the fetus is occurring earlier in prenatal development through noninvasive methods

  
• Behavior genetics


  The field concerned with the influence of heredity and environment on individual differences in human traits and development
• Twin studies


  • Twins share their DNA which makes it easier to study the effects of the environment
  • Helps identify the cause of several mental disorders
  • Allows researchers to identify dominant genes causing a particular trait
  • Used to estimate the heritability of traits and the effect of shared and unique environments
• Genotype-environment correlation


  Heredity directs the types of environments that children experience, including passive, evocative, and active (niche-picking) correlations

  
• The relative importance of genotype-environment correlations changes as children develop
• Shared and non-shared environmental experiences

  Contribute to similarities and differences between siblings
• Epigenetic view

  • Development is the result of an ongoing, bidirectional interchange between heredity and environment
  • Gene × environment interaction involves the interaction of a specific measured variation in the DNA and a specific measured aspect of the environment

  
• Behaviors are influenced by genes and environments in a way that gives people a propensity for a particular developmental trajectory
• Actual development requires both genes and an environment, and that environment is complex
• A pregnant woman's cravings will not affect the baby's appearance
• Wearing necklaces or wrapping towels around the neck will not cause the umbilical cord to wrap around the baby's neck
• Attending funerals will not cause a stillborn or the baby to be taken by vengeful spirits
• Eating twin bananas or eggs with twin yolks will not increase the chances of having twins
• Sewing or stepping over ropes will not lead to labor difficulties
• Dark spots on the body will not determine the baby's gender
• Pregnancy superstitions should not replace proper prenatal care to address the baby's needs and the mother's health