Introduction to Physiological Psychology

Modified: 2026-08-05 11:15 AM CDST

• In the same way that we think of a car's motor as its source of propulsion, we can think of our body's muscles in the same way.
  • So, physiology underlies behavior in some highly complex ways, and a complete understanding of psychology would necessarily include some knowledge of physiology.
• Note that I used the words "in a highly complex way" in the previous sentence.
  • Some estimate such knowledge of physiology is still some 300 years away.

Some interesting philosophical problems also underlie physiological psychology.

• One is the identity problem.
  • In mathematics, an identity is a fundamental property of a field.
  • For example, when I specify a number, say the number 2, then the identity property ensures that whenever I say 2, I mean the same number. In other words, 2 is always 2.
  • That is a mathematical identity.
• In physiological psychology, the identity problem is whether or not brain = behavior. Is that an identity?
  • If I knew my brain completely would I then know my behavior completely?
    • Unfortunately, we do not yet know if there is an identity between brain and behavior.
  • Some researchers and philosophers would be very happy to maintain that there is, and we just have not yet found it (300 more years, remember?).
    • Others maintain that the brain = behavior identity is not an identity, and no amount of work will show it to be one.

Another interesting philosophical problem in physiological psychology is the continuity problem.

• This problem revolves around the relationship of humans to other animals.
  • In nonscientific circles, such as religions, the answer is clear.
  • Humans are qualitatively different than the other animals, or, in other words, humans and animals are different kinds of entities.
    • In scientific circles, however, the picture is different.
    • Since 1859, when Darwin published the Origin of the Species, humans have been seen not as different kinds of entities, but as different by degree from the other animals in other words, as part of the same continuum.
  • Continuity, then, means that humans are more similar than they are different from the other animals.
    • Some have argued that continuity merely reflects a larger trend that has been in motion since the late Middle Ages, a trend of loss of uniqueness.
      • Humans have gradually been losing their claims as being uniquely different since Copernicus proposed that the Earth is not the center of the universe.