Developmental Psychology Overview

Study of Development

• Cross-Sectional Survey - Examines different age groups at the same time.
  • Pros - Efficient way to study developmental trends.
  • Cons - Cannot analyze the same individuals over time.
  • Example - Comparing the vocabulary of 5-year-olds, 10-year-olds, and 15–year-olds.
• Independent Variables - The factor that is manipulated or changed by the researcher in an experiment.
• Dependent Variables - The factor that is measured in an experiment to see how it is affected by the independent variable.
• Longitudinal Design - Studies the same individuals over a period of time.
  • Pros - Provides insights into developmental changes over time.
  • Cons - Time-consuming, expensive, and can be affected by participant attrition.
  • Example - Tracking the development of language skills in the same group of children from ages 2-5.
• True Experiment - An experiment that uses random assignment to control for confounding variables.
  • Pros - Offers the strongest evidence of cause and effect.
  • Cons - Can be difficult or unethical to conduct.
  • Example - Randomly assigning students to different teaching methods to see which method leads to greater academic gains.
• Cross-Sectional Studies - Limitations include inability to establish cause-and-effect relationships and potential cohort effects (differences between age groups due to historical or cultural factors).
• Qualitative Studies - Focus on in-depth understanding of experiences, perspectives, and meanings.
  • Examples - Interviews, ethnographic observations.
• Qualitative Research - Explores complex social phenomena through non-numerical data.
  • Pros - Provides rich, nuanced insights.
  • Cons - Can be subjective and difficult to generalize.
• Quantitative Research - Uses numerical data and statistical analysis to test hypotheses.
  • Pros - Allows for comparisons and generalizations.
  • Cons - Can overlook complex or nuanced aspects.
• Operational Definition - Defines a concept in terms of specific, observable, and measurable procedures.
  • Example - Defining intelligence as a score on an IQ test.
• H.M. - A famous case study of a patient who had surgery to remove part of his hippocampus.
  • Key Takeaways - Revealed the hippocampus's crucial role in forming new memories.
• Facilitated Communication - A method used to communicate with individuals with severe disabilities.
  • Status - Lack of scientific support; studies have shown that facilitators often unconsciously influence the communication, not the individuals they claim to be assisting.
  • Use - Despite lack of support, some individuals and families still find it helpful.
• Cell phones in College Classrooms - Research on cell phone use in classrooms is ongoing.
  • Concerns - Potential distractions, impact on learning, and fairness in academic assessment for students who do not have access to or are prohibited from using cell phones.

Genetic Aspects of Development

• Iceland - High rates of Down syndrome due to genetic factors.
• Concordance Rate - The probability that two individuals will share a particular trait, based on their genetic relatedness.
  • Example - The concordance rate for schizophrenia between identical twins is higher than that for fraternal twins.
• Reaction Range - The range of possible phenotypes that can result from a specific genotype.
  • Example - Potential for height, influenced by both genetics and environmental factors.
• Codominance - Both alleles are expressed equally in the phenotype.
  • Example - Blood type AB: both A and B antigens are expressed.
• Incomplete Dominance - One allele is not completely dominant over the other, resulting in a blended phenotype.
  • Example - Red flowers crossed with white flowers produce pink flowers.
• Tay-Sachs Disease - A recessive genetic disorder that affects the nervous system.
• Hemophilia - A recessive genetic disorder that affects blood clotting.
• Phenylketonuria (PKU) - A recessive genetic disorder that affects metabolism.
• Embryonic Structure for Brain and Spinal Cord - The neural tube forms during the first few weeks of gestation.
• Huntington's Disease - A dominant genetic disorder that causes progressive degeneration of the nervous system.
• BRCA1 and BRCA2 - Genes associated with an increased risk of breast and ovarian cancer.
  • Rates - People with mutations in these genes have a significantly higher chance of developing these cancers.
• Sex Chromosome Abnormalities - Affect the development of sexual characteristics.
  • Common Phenotypic Expression - Turner Syndrome (XO), Klinefelter Syndrome (XXY), and Jacob's Syndrome (XYY).
• Indications for Genetic Counseling - Family history of genetic disorders, advanced maternal age, individuals with unexplained infertility, before a pregnancy, or after the birth of a child with genetic conditions.

This quiz explores key concepts in developmental psychology, including research designs such as cross-sectional surveys and longitudinal studies. It examines the definitions of independent and dependent variables, and the pros and cons of different research methods. Test your knowledge of how these methodologies apply to studying development across different age groups.