Lecture 1: Health Psychology, Research Methods, and Bodily Systems || PSY260: Health Psychology

Summary

The lecture introduces health psychology, its historical development, the scientific methods it uses, and several bodily systems relevant to health.

What health psychology studies

• Health is more than the absence of illness; it includes physical, mental, and social well-being.
• Health psychology applies psychological principles and research to promote health and help prevent or treat illness.
• Wellness is described as having six dimensions: mental, spiritual, emotional, physical, environmental, and social health.

Historical and conceptual models of health

• Early cultures, including those of ancient Egypt, China, and India, often explained illness through mystical forces or spirits.
• René Descartes’ idea of mind–body dualism treated the mind and body as separate.
• The biomedical model explains disease primarily through biological causes, such as viruses or bacteria. The lecture notes that this model can overlook psychological, social, and behavioral influences.
• The growth of health psychology is linked to longer life expectancy, more preventable lifestyle-related disorders, rising health-care costs, and movement beyond a strictly biomedical view.
• The biopsychosocial approach considers biological, psychological, and social factors together. An ecological perspective likewise emphasizes how these forces interact in shaping health and illness.

Critical thinking and research methods

Scientific inquiry requires critical thinking: avoiding snap judgments, recognizing potential bias, and questioning assumptions. Statistical literacy is important for evaluating statistics used as evidence.

The lecture distinguishes several research approaches:

• Descriptive studies include case studies, surveys, and observational studies. They describe people or situations but do not manipulate variables as experiments do. They may be affected by bias, including observer bias.
• Correlational studies measure two or more variables to see whether they are related. A relationship may be:
  • None: The variables show no relationship.
  • Positive: As one variable increases, the other tends to increase.
  • Negative: As one variable increases, the other tends to decrease.

Correlation alone does not establish that one variable causes the other.

• Experimental studies manipulate an independent variable to examine its effect on a dependent variable. A true experiment requires randomly assigning participants to conditions. Some health questions cannot ethically or practically be studied experimentally.

Health psychologists also draw on:

• Epidemiology, the study of how often diseases occur in different groups and why.
• Cross-sectional and longitudinal studies to investigate possible effects of age.
• Qualitative research, which can give greater attention to patients’ experiences.
• Other designs, such as retrospective and prospective studies, laboratory experiments, randomized clinical trials, and meta-analyses.

Epidemiological measures

• Morbidity: Illness in a population, including the number of cases of a disease.
• Incidence: The number of new cases during a specified period.
• Prevalence: The total number of existing cases at a given time.
• Mortality: The number of deaths from a disease during a specified period.

Research in health psychology must protect participants’ rights and well-being and follow professional ethical guidelines, such as those of the American Psychological Association (APA).

Bodily systems introduced

The lecture surveys five systems and their roles in health:

• Nervous system: Coordinates thoughts, emotions, and movement. It includes the central nervous system (brain and spinal cord) and the peripheral nervous system, which connects the rest of the body to it.
• Endocrine system: Uses hormones to regulate processes such as metabolism, growth, development, mood, and stress responses.
• Cardiovascular system: The heart, blood, and blood vessels deliver oxygen, nutrients, and hormones to cells and carry away waste.
• Immune system: Defends the body against pathogens using components such as white blood cells and antibodies.
• Digestive system: Breaks food down into usable nutrients. The lecture also highlights the gut microbiome: gut bacteria help process food and are linked to the central nervous system.

Overall, health emerges from interacting biological, psychological, and social influences. Understanding it requires both scientific inquiry and attention to the body’s interconnected systems.

Speakers and sources featured

• Speaker: The lecture’s narrator/instructor, identified by the course context as Dr. Alexander (Alex) Swan.
• Sources or frameworks mentioned: René Descartes, the Global Wellness Institute, the American Psychological Association (APA), and epidemiology as a field of study. No other speakers are identified.