Biopsychology is a branch of psychology that analyzes how the brain, neurotransmitters, and other aspects of our biology influence our behaviors, thoughts, and feelings. This field of psychology is often referred to by a variety of names including biopsychology, physiological psychology, behavioral neuroscience, and psychobiology. Biopsychologists often look at how biological processes interact with emotions, cognitions, and other mental processes.

The field of biopsychology is related to several other areas, including comparative psychology and evolutionary psychology.

While biopsychology might seem like a fairly recent development thanks to the introduction of advanced tools and technology for examining the brain, the roots of the field date back thousands of years to the time of the early philosophers. While we now consider the mind and brain synonymous, philosophers and psychologists long debated what was known as the mind/body problem. In other words, philosophers and other thinkers wondered what the relationship was between the mental world and the physical world.