Introduction to Biological Psychology

Modified: 2026-08-05 10:17 AM CDST

• Aristotle was one of the first to study living things systematically. His descriptions of animals and plants stood as authoritative for centuries.
• The Hippocratic humoral tradition in medicine lasted, nearly unaltered, into the 18th century.
• Medicine was always linked to biology but its early practitioners were held in lower esteem compared to philosophers or theologians.
• By the 19th century, however, biology became a scientific and empirical science following in the earlier footsteps of physics and chemistry. The invention of the microscope revealed a previously unknown living universe beneath the threshold of vision.
• The discovery of gigantic fossilized bones helped destroy the older idea that the living things present on earth had existed unaltered since the beginning of time. Geologists gradually added more and more years to the age of the earth, moving its age from a few thousand years to a few billion. By the end of the 19th century, the science of biology had been completely transformed.
  
• Darwin’s evolutionary theory provided a profound unifying, explanatory structure for many previously difficult to explain phenomena.
• Gregor Mendel’s research in genetics, although ignored until its rediscovery in the 20th century, provided some of the missing pieces required to explain how evolution worked at the molecular level leading to biology’s modern synthesis, the union of evolutionary and genetic theories in the early 20th century.
• Watson and Crick’s model of the DNA molecule in 1953 (aided by Rosalind Franklin’s crystallographic images) launched a new era in biology during the latter half of the century as researchers began to delve more deeply into the machinery of life itself.
• Modern biology is a relatively young science, another child of the Newtonian revolution, but unlike physicists and chemists, biologists study living things. Those living things change over time, exhibit far greater variability, and resist easy theoretical explanations of their underlying mechanisms compared to the objects of study of physics and chemistry (Kagan, 2009).

• Biology is one of the sources of psychology.
• Genetics, evolution, hormones, physiological and brain mechanisms help explain and help us understand psychology.
• Your textbook emphasizes brain mechanisms but also discusses other major issues:
  • mind and brain
  • nature vs. nurture
  • ethical constraints on research
• In addition, I will bring in biological issues from the areas of:
  • comparative psychology
  • ethology
  • animal behavior
  • All of the above deal with the broad basis of behavior in humans and other animals

Two Questions

• Why is there something rather than nothing? (Leibniz)
  • Kalat demonstrates the many factors that enable life on earth:
    • Gravity
    • Electromagnetism
    • The formation of elements
    • The strong force and electromagnetic force
    • The ratio of electromagnetic force to gravity
    • The mass of the neutron
    • Liquid water
  • Every living thing is constrained by the factors above
  • Other universes?
    • Are there any? Star Wars Bar Scene
    • If there are any, are they subject to the same physical factors?
• What is the relationship between mind and body?
  • Long-standing philosophical problem
    • How do you know the world was not created two hours ago and all of us given a stock of false memories?
    • (You don't, could be true and we'd never know.)
    • Phillip K. Dick stories plsy with such questions
      • Do Androids Dream of Electric Sheep (a.k.a. Blade Runner) review1,
      • We Can Remember it for You Wholesale (a.k.a.Total Recall) review
      • Dick imagined the limits of reality and our ability to comprehend it.
      • More information on Phillip K. Dick (This section not on any test)
  • No real answers to the Mind-Body, but solution colors your view of the world
  • Mind-Body Solutions show historical progression from Middle Ages through Descartes to Modern times
    • Monistic Solutions (either mind or body)
      • materialism--only body is real (thinking is product of brain activity)
      • idealism--only mind is real (the mind creates the appearance of a physical world)
    • Dualistic Solutions (both mind and body, in some fashion)
      • interactionism--Descartes solution, body and mind affect each other
        • This solution, though seductive, cannot determine where the linkage between the two is
        • Descartes believed it was in the pineal gland but that has been disproven
      • epiphenomenalism--mind exists, but has no power, is created by body (brain)
        • Here, the brain runs things, creates the illusion of an active mind
      • double-aspectism--both exist, are inseperable, are like mirror-images
        • Here, both exist but are just different interpretations of reality
        • The Matrix movies play on this solution
        • That movie nicely illustrated the pre-established harmony Mind-Body solution
          • In the movie most people believe they are living normal lives (the mind)
          • In reality, however, they have been imprisoned by machines and are stuck away in a dark place where their bodies are being used for energy (the reality)
          • Neo, the hero, makes a choice (swallows the Red Pill--video) to live in the real world and to defeat the machines
            • If you have not seen the movie you should watch the video above
          • The real world in The Matrix, a pod
            • That is the Body side, humans trapped in a dark place, providing energy for the machines
            • On the Mind side, those trapped humans believe they are living normal lives
          • Want more explanation? Read Really Good Noodles
      • parallelism--both Mind and Body exist, but they do not affect each other, they are on parallel tracks
        • Thus, they occur at same time but constitute two separate realities, one physical, one mental
      • occasionalism--both exist, but from time to time rules are broken (i.e., miracles)
        • This solution is not much supported because it is not consistent
      • pre-established harmony--both exist, do not interact, are like two clocks started at same time
        • Isaac Newton believed in this solution. He believed that God had set and started the two separate tracks of Mind and Body but did not interfere further. Thus, his clock metaphor
    • As you might imagine, a course in physiological psychology is going to be heavily weighted on the Body side

Biological Psychologyh

• The connection between psychology and biology is ancient dating back to Aristotle's research
  • Other terms: biopsychology, psychobiology, physiological psychology, behavioral neuroscience, and more...
    • All stress the importance of brains (of all types), neural networks, and sensory organs
      • (All of those will be topics in this course)
  • Three Main Points
    • Perception is internal
      • Perception is the interpretation of sensory information
    • Monistic explanations predominate in biological psychology (e.g. materialism or epiphenomenalism)
  • What constitutes a satisfactory scientific explanation?
  • Types of Explanations (see if you can come up with other examples)
    • Physiological
      • e.g., Humans like sweet tastes
    • Ontogenetic (e.g., developmental)
      • e.g., male adolescents are more reckless
    • Evolutionary (life history, why do we have two arms and two legs?)
      • e.g., Teleost fish evolved front and rear fins, those bony structures evolved into mammalian forelimbs and hindlimbs
• If humans had evolved from insects how many limbs would we have? (6, see why?)
• Functional (Biston betularia and industrial melanism)
• Read the link above to see how peppered moth populations changed in response to pollution and its abatement
• Many career opportunities in biological psychology
  • APA on neuropsychology
• Use of animals in research
  • Controversial, so ethical guidelines exist
    • APA Guidelines for Use of Animals in Research
      • Reasons for using animals
        • Similar underlying physiological mechanisms
        • Because (in other words: we want to know about other animals too)
        • Evolutionary linkages
        • Cannot use humans in certain studies (can you think of examples?)
          • e.g., What would happen if I raised 500 boys as girls and 500 girls as boys for 18 years?
            • There are many ethical reasons why I could not do so.
          • Recall the Nazi "experiments" on humans by Mengele and others
            • Their results were so unethical that the US government has forbidden their use
      • Animal research must be ethical
        • Research must:
          • Have "clear scientific purpose"
          • Be "of sufficient potential significance to justify use of nonhuman animals"
          • Conducted by persons expert in the literature and procedures
          • Consider nonanimal procedures
          • Be cleared by the appropriate IRB
          • Monitor animals's welfare
  • IRBs
    • SAU has two: Human Subjects and Animal Subjects
    • PETA (People for the Ethical Treatment of Animals)
      • "PETA opposes speciesism"
      • Works to oppose mistreatment of animals in laboratories, food industry, clothing trade, and entertainment business
    • Abolitionists vs. Minimalists
      • Abolitionists
        • Against all animal research
        • May harrass and intimidate researchers
      • Minimalists
        • Follow the three R's
          • Reduction: Use as few animals as possible
          • Replacement: See research methods that avoid the use of animals
          • Refinement: Use procedures designed to reduce or eliminate animal pain or discomfort
    • Legal Standards
      • Vary by country
      • See Great Ape personhood

Biological Physiology

• There are many areas of physiological study that are of less interest to psychology. We will NOT addess those. They include:
  • Cardiovascular
  • Cell
  • Molecular
  • Oncology
  • Digestion
  • Immunology
  • Renal/Urinary
  • Respiratory
  • And more...
• Note, the above areas of physiology are of vital importance. They lean more to the medical side of biology.

Reference

Kagan, J. (2009). The three cultures: Natural sciences, social sciences and the humanities in the 21st century. Cambridge: Harvard University Press.

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