Saul McLeod, updated 2015
The biological approach believes us to be as a consequence of our genetics and physiology. It is the only approach in psychology that examines thoughts, feelings, and behaviors from a biological and thus physical point of view.
Therefore, all that is psychological is first physiological. All thoughts, feeling & behavior ultimately have a biological cause. A biological perspective is relevant to the study of psychology in three ways:
1. Comparative method: different species of animal can be studied and compared. This can help in the search to understand human behavior.
2. Physiology: how the nervous system and hormones work, how the brain functions, how changes in structure and/or function can affect behavior. For example, we could ask how prescribed drugs to treat depression affect behavior through their interaction with the nervous system.
3. Investigation of inheritance: what an animal inherits from its parents, mechanisms of inheritance (genetics). For example, we might want to know whether high intelligence is inherited from one generation to the next.
Each of these biological aspects, the comparative, the physiological (i.e., the brain) and the genetic, can help explain human behavior.
Investigation of Inheritance
Twin studies provide geneticists with a kind of natural experiment in which the behavioral likeness of identical twins (whose genetic relatedness is 1.0) can be compared with the resemblance of dizygotic twins (whose genetic relatedness is 0.5).
In other words, if heredity (i.e., genetics) affects a given trait or behavior, then identical twins should show a greater similarity for that trait compared to fraternal (non-identical) twins.
There are two types of twins:
Monozygotic = identical twins (share 100% genetic information).
Dizygotic = non-identical twins (share 50% genetic information, similar to siblings).
Research using twin studies looks for the degree of concordance (or similarity) between identical and fraternal (i.e., non-identical) twins. Twins are concordant for a trait if both or neither of the twins exhibits the trait. Twins are said to be disconcordant for a trait if one shows it, and the other does not.
Identical twins have the same genetic make-up, and fraternal twins have just 50 per cent of genes in common. Thus, if concordance rates (which can range from 0 to 100) are significantly higher for identical twins than for fraternal twins, then this is evidence that genetics play an important role in the expression of that particular behavior.
Bouchard and McGue (1981) conducted a review of 111 worldwide studies which compared the IQ of family members. The correlation figures below represent the average degree of similarity between the two people (the higher the similarity, the more similar the IQ scores).
Identical twins raised together = .86 (correlation).
Identical twins raised apart = .72
Non-identical twins reared together = .60
Siblings reared together = .47
Siblings reared apart = .24
Cousins = .15
However, there are methodological flaws which reduce the validity of twin studies. For example, Bouchard and McGue included many poorly performed and biased studies in their meta-analysis. Also, studies comparing the behavior of twin raised apart have been criticized as the twins often share similar environments and are sometimes raised by non-parental family member.
Methods of Studying the Brain
It is important to appreciate that the human brain is an extremely complicated piece of biological machinery. Scientists have only just “scratched the surface” of understanding the many functions of the workings of the human brain. The brain can influence many types of behavior.
In addition to studying brain damaged patients, we can find out about the working of the brain in three other ways.
Children begin to plan activities, make up games, and initiate activities with others. If given this opportunity, children develop a sense of initiative and feel secure in their ability to lead others and make decisions.
1. Neuro Surgery
We know so little about the brain and its functions are so closely integrated that brain surgery is usually only attempted as a last resort. H.M. suffered such devastating epileptic fits that in the end a surgical technique that had never been used before was tried out.
This technique cured his epilepsy, but in the process the hippocampus had to be removed (this is part of the limbic system in the middle of the brain.) Afterwards, H.M. was left with severe anterograde amnesia. I.e., He could remember what happened to him in his life up to when he had the operation, but he couldn’t remember anything new. So now we know the hippocampus is involved in memory.
2. Electroencrphalograms (EEGs)
This is a way of recording the electrical activity of the brain (It doesn’t hurt, and it isn’t dangerous!). Electrodes are attached to the scalp and brain waves can be traced. EEGs have been used to study sleep, and it has been found that during a typical night’s sleep, we go through a series of stages marked by different patterns of brain wave.
One of these stages is known as REM sleep (Rapid Eye Movement sleep). During this, our brain waves begin to resemble those of our waking state (though we are still fast asleep) and it seems that this is when we dream (whether we remember it or not).
3. Brain Scans
More recently methods of studying the brain have been developed using various types of scanning equipment hooked up to powerful computers. The CAT scan (Computerised Axial Tomography) is a moving X-ray beam which takes “pictures” from different angles around the head and can be used to build up a 3-dimensional image of which areas of the brain are damaged.
Even more sophisticated is the PET scan (Positron Emission Tomography) which uses a radioactive marker as a way of studying the brain at work. The procedure is based on the principle that the brain requires energy to function and that the regions more involved in the performance of a task will use up more energy. What the scan, therefore, enables researchers to do is to provide ongoing pictures of the brain as it engages in mental activity.
These (and other) methods for producing images of brain structure and functioning have been extensively used to study language and PET scans, in particular, are producing evidence that suggests that the Wernicke-Gerschwind model may not after all be the answer to the question of how language is possible.
History of The Biological Approach
Biological Approach Summary
Theories within the biological approach support nature over nurture. However, it is limiting to describe behavior solely in terms of either nature or nurture, and attempts to do this underestimate the complexity of human behavior. It is more likely that behavior is due to an interaction between nature (biology) and nurture (environment).
For example, individuals may be predisposed to certain behaviors, but these behaviors may not be displayed unless they are triggered by factors in the environment. This is known as the ‘Diathesis-Stress model’ of human behavior.
A strength of the biological approach is that it provides clear predictions, for example, about the effects of neurotransmitters, or the behaviors of people who are genetically related. This means the explanations can be scientifically tested and ‘proven.’
A limitation is that most biological explanations are reductionist, as it reduces behavior to the outcome of genes and other biological processes, neglecting the effects of childhood and our social and cultural environment. and don’t provide enough information to fully explain human behavior.
Bouchard, T. J., & McGue, M. (1981). Familial studies of intelligence: A review. Science, 212(4498), 1055-1059.
Darwin, C. (1859). On the Origin of Species by Means of Natural Selection, or the Preservation of Favoured Races in the Struggle for Life (1st ed.). London: John Murray.
Harlow, J. M. (1848). Passage of an iron rod through the head. Boston Medical and Surgical Journal, 39, 389–393.
Tooby, J., & Cosmides, L. (1992). The psychological foundations of culture. In J. Barkow, L. Cosmides, & J. Tooby (Eds.), The adapted mind: Evolutionary psychology and the generation of culture. New York: Oxford University Press.
Wilson, E. (1975). Sociobiology: The New Synthesis. Harvard University Press
How to reference this article:
McLeod, S. A. (2015). Biological psychology. Retrieved from www.simplypsychology.org/biological-psychology.htmlListen to a MIT undergraduate lecture on Love and Evolution.
Psychology should be seen as a science, to be studied in a scientific manner.
Behavior can be largely explained in terms of biology (e.g., genes/hormones).
Human genes have evolved over millions of years to adapt behavior to the environment. Therefore, most behavior will have an adaptive / evolutionary purpose.
The biological approach provides clear predictions that can. This means that explanations can be scientifically tested and support with evidence.
Real life applications (e.g., therapy)
Emphasizes objective measurement
Many experiments to support theories
Highly application to other areas: Biology + Cog = Evolutionary Psy
There are many different ways of thinking about topics in psychology. The biological perspective is a way of looking at psychological issues by studying the physical basis for animal and human behavior. It is one of the major perspectives in psychology and involves such things as studying the brain, immune system, nervous system, and genetics.
One of the major debates in psychology has long centered over the relative contributions of nature versus nurture.
Those who take up the nurture side of the debate suggest that it is the environment that plays the greatest role in shaping behavior. The biological perspective tends to stress the importance of nature.
The Biological Perspective on Psychology
This field of psychology is often referred to as biopsychology or physiological psychology. This branch of psychology has grown tremendously in recent years and is linked to other areas of science including biology, neurology, and genetics.
The study of physiology and biological processes has played a significant role in psychology since its earliest beginnings. It was Charles Darwin who first introduced the idea that evolution and genetics play a role in human behavior. Natural selection influences whether certain behavior patterns are passed down to future generations. Behaviors that aid in survival are more likely to be passed down while those that prove dangerous are less likely to be inherited.
The biological perspective is essentially a way of looking at human problems and actions. Consider an issue like aggression, for example. Someone using the psychoanalytic perspective might view aggression as the result of childhood experiences and unconscious urges. Another person might take a behavioral perspective and consider how the behavior was shaped by association, reinforcement, and punishment.
A psychologist with a social perspective might look at the group dynamics and pressures that contribute to such behavior.
The biological viewpoint, on the other hand, would involve looking at the biological roots that lie behind aggressive behaviors. Someone who takes the biological perspective might consider how certain types of brain injury might lead to aggressive actions. Or they might consider genetic factors that can contribute to such displays of behavior.
What Sort of Things Are Biological Psychologists Interested In?
Biopsychologists study many of the same things that other psychologists do, but they are interested in looking at how biological forces shape human behaviors. Some topics that a psychologist might explore using this perspective include:
- Analyzing how trauma to the brain influences behaviors
- Investigating how degenerative brain diseases impact how people act
- Exploring how genetic factors influence such things as aggression
- Studying how genetics and brain damage are linked to mental disorders
- Assessing the differences and similarities in twins to determine which characteristics are tied to genetics and which are linked to environmental influences
This perspective has grown considerably in recent years as the technology used to study the brain, and nervous system has grown increasingly advanced.
Today, scientists use tools such as PET and MRI scans to look at how brain development, drugs, disease, and brain damage impact behavior and cognitive functioning.
Reasons to Take a Biological Perspective
One of the strengths of using the biological perspective to analyze psychological problems is that the approach is usually very scientific. Researchers utilize rigorous empirical methods, and their results are often reliable and practical. Biological research has helped yield useful treatments for a variety of psychological disorders.
The weakness of this approach is that it often fails to account for other influences on behavior.
Things such as emotions, social pressures, environmental factors, childhood experiences, and cultural variables can also play a role in the formation of psychological problems. For that reason, it is important to remember that the biological approach is just one of the many different perspectives in psychology. By utilizing a variety of ways of looking a problem, researchers can come up with different solutions that can have helpful real-world applications.
A Word From Verywell
There are many different perspectives from which to view the human mind and behavior and the biological perspective represents just one of these approaches. By looking at the biological bases of human behavior, psychologists are better able to understand how the brain and physiological processes might influence the way people think, act, and feel. This perspective also allows researchers to come up with new treatments that target the biological influences on psychological well-being.
Hockenbury, DH & Hockenbury SE. Discovering Psychology. New York: Worth Publishers; 2011.
Pastorino, EE, Doyle-Portillo, SM. What Is Psychology? Foundations, Applications, and Integration. Boston, MA: Cengage Learning; 2015.