Biological psychology involves studying biological influences on behavior, thoughts, and emotions (Kalat, 2015).
Biological psychology primarily focuses on the nervous system, hormones, and genetics. These biological influences are intertwined with each other and environmental influences, making the path from biology to behavior highly complex.
This specialty within psychology may use both human and animal-model research methods.
This is a rapidly growing and changing field. As scientific techniques advance and become cheaper, more researchers can use innovative methods to understand biological processes involved in various behavioral outcomes, including mental health, cognition and learning, and much more (Lyons et al., 2014).
Note: Biological psychology is sometimes called biopsychology, physiological psychology, and psychobiology (APA).
Definition of Biological Psychology
Biological psychology is a broad field that seeks to identify biological explanations of behavior (Kalat, 2015).
Biological psychology suggests that humans think and act the way we do because of brain mechanisms and activity.
A critical concept in biological psychology is that perception occurs in your brain (Kalat, 2015).
For example, if you accidentally touch a hot stove, the nerves in your hand send a signal to your brain. So, you feel that burn in your brain, not your hand. This applies to more than just pain but also other modes of perception, like vision.
Biological psychology is concerned with both proximate and ultimate questions:
- Proximate questions concern immediate and mechanistic influences on behavior,
- Ultimate questions concern larger historical and evolutionary influences (Lyons et al., 2014).
Biological psychology encompasses research methods, including studying behavior concerning brain activity, hormones, and genetics.
10 Biological Psychology Examples
- The study of brain activity. A scientist is interested in understanding how the brain operates while someone is reading. This scientist may design an fMRI study and have people complete a specific reading task while in the scanner. Then the scientist can see what regions of the brain activate while someone is reading.
- Lesion studies. Lesion studies were prevalent in early biological psychology and neuroscience. These studies looked for associations between damage or abnormalities in brain tissue and behavior. A classic example is Phineas Gage. Gage experienced major damage to his frontal lobe in a construction accident. He survived, but his personality changed, and he lost his ability to self-regulate and inhibit his impulses. Scientists studied Gage and began understanding that the frontal lobe was important to personality and self-regulation.
- The study of hormones. Biological psychology can concern with how hormones influence behavior. Hormones are chemical messengers that are released by specific glands and travel in the bloodstream. Hormone levels can be increased or decreased by specific situations. For example, cortisol, a stress hormone, may increase in a frightening situation and influence behavior by impacting your attention.
- Twin Studies. Twin and family studies provide an aggregate estimate of genetic influences on variability in behavioral or psychological outcomes by examining differences between people who share different amounts of DNA. For example, early twin and family research was important to understanding that a significant genetic component played a role in why some people develop schizophrenia (Knopik et al., 2016). In addition, twin studies consistently found that genetic and environmental influences are important to almost all human behavior.
- GWAS. GWAS are a recent and popular development in biological psychology. GWAS findings have backed up much of the twin and family literature. GWAS have also made large advances in our understanding of genetics and behavior. For example, GWAS have demonstrated that many (sometimes thousands) genes have tiny effects, on behavior, rather than a few genes having large effects.
- Epigenetics. Epigenetics is another method used in biological psychology. Epigenetics is concerned with gene regulation and expression, specifically methylation. Environmental factors, like poverty, can impact methylation and gene expression. For example, researchers have found that people who have experienced poverty have faster biological aging, indicated by DNA methylation (Raffington & Belsky, 2022).
- Asking Proximate Questions. Proximate questions deal with immediate and mechanistic influences on behavior. For example, a hormone researcher may be interested in the link between puberty and mental health. They think specific hormones that increase in puberty, like testosterone in males, may partially explain the increase in mental health issues or risk-taking behavior observed in teenage boys. If the researcher found a connection between testosterone and aggression, that would be a proximate explanation.
- Animal-models. Researchers can use animal-models, like rat or mouse models, to examine questions related to biology and behavior. For example, researchers can alter the genetic makeup of a model-animal, expose the animals to specific environmental influences and examine DNA methylation, or perform lesion studies.
- Studying candidate genes and false positives. Not all research methods in biological psychology have stood the test of time. Candidate gene studies were popular when psychologists first started using measured genetics in their research. Unlike the GWAS, candidate gene studies would typically look at if one specific gene related to behavior. We now know that single genes have very tiny effects on behavior. Candidate gene studies were particularly popular in gene by environment studies (GxE), where researchers examine if the effect of a gene or genetic influences depends on environmental contexts. Though twin studies have demonstrated GxE, researchers have shown that many candidate GxE findings were likely false positives (Duncan & Keller, 2011).
- Working in correlation studies. Biological psychology requires careful interpretation because a great deal of the studies explore correlations (not causations). For example, a researcher may find that specific brain structure differences are related to differences in depression symptoms. However, this doesn’t tell us that that brain region causes depression.
Common Biological Psychology Research Methods & Tools
1. Brain Imaging
There are several brain imaging techniques used in biological psychology. These techniques can provide information about the brain’s structure or function (activity) (Lyons et al., 2014).
Techniques that provide information about the brain’s structure include CT scans and magnetic resonance imaging (MRI). Functional techniques that infer brain activity include PET scans and functional MRI (fMRI).
2. Electrophysiological Tools
Biological psychology also relies on electrophysiological tools to directly measure the activity of either single nerve cells or large groups of nerve cells. One of the most popular electrophysiological techniques is electroencephalography (EEG).
3. Behavioral Genetics
Biological psychology also relies on measuring genetic makeup or hormone levels and seeing if those influences correlate with specific behavioral and psychological outcomes. The study of genetic and environmental influences on behavior is known as behavioral genetics and is also sometimes called sociogenomics (Harden, 2021).
Behavioral genetics typically uses either twin/family studies or genome-wide association studies (GWAS) to understand how genetic and environmental influences contribute to variability in human behavior and psychological outcomes (Harden, 2021).
Twin studies compare how similar identical and fraternal twins are on a specific outcome and then use specific statistical models to estimate genetic and environmental influences on that outcome. GWAS involves testing correlations between an outcome and many measured genetic differences across the genome.
Other Types of Psychology
- Evolutionary Psychology – Evolutionary psychology aims to understand how thoughts, actions, and behavior are shaped by evolutionary forces (Mealey, 2023; Workman, 2004).
- Clinical Psychology – Clinical Psychology is a specialty in psychology that involves the practical application of psychological theories for treating psychological problems and disorders (Pomerantz, 2016).
Biological psychology is concerned with biological explanations and influences of human behavior. Though biological psychology uses impressive and advanced tools, it is important to remember that most of the work is still correlational, and it is very hard to identify true causation.
APA Dictionary of Psychology. (n.d.). Retrieved January 23, 2023, from https://dictionary.apa.org/
Duncan, L. E., & Keller, M. C. (2011). A Critical Review of the First 10 Years of Candidate Gene-by-Environment Interaction Research in Psychiatry. American Journal of Psychiatry, 168(10), 1041–1049. https://doi.org/10.1176/appi.ajp.2011.11020191
Harden, K. P. (2021). “Reports of My Death Were Greatly Exaggerated”: Behavior genetics in the postgenomic era. Annual Review of Psychology, 72(1), null. https://doi.org/10.1146/annurev-psych-052220-103822
Kalat, J. W. (2015). Biological Psychology. Cengage Learning.
Knopik, V. S., Neiderhiser, J. M., DeFries, J. C., & Plomin, R. (2016). Behavioral Genetics (Seventh edition). Worth Publishers.
Lyons, M., Harrison, N., Brewer, G., Robinson, S., & Sanders, R. (2014). Biological Psychology. Learning Matters.
Raffington, L., & Belsky, D. W. (2022). Integrating DNA Methylation Measures of Biological Aging into Social Determinants of Health Research. Current Environmental Health Reports, 9(2), 196–210. https://doi.org/10.1007/s40572-022-00338-8
Dr. Chris Drew is the founder of the Helpful Professor. He holds a PhD in education and has published over 20 articles in scholarly journals. He is the former editor of the Journal of Learning Development in Higher Education.