The human being, as one of the most complex animals that exist, is the object of study of an infinite number of sciences. They try to unravel its mysteries and nature on the physical or organic plane, as well as on the psychological, social or spiritual plane.

Two of these sciences are psychology and physiology, two disciplines at the center of which is research and understanding of human functioning. Thanks to them, we know many things about how we react to different situations and how we adapt to the environment. However, there are substantial differences between physiology and psychology , which we will try to elucidate throughout this article.

Psychology and Physiology: the two parts of a whole

From a general perspective, we can conceive the human being as a whole formed by different planes, which could not live without each other. These planes refer to the physical or organic aspect of the person and the psychological aspect, related to behavior and emotions.

Throughout the history of humanity, sciences were created and developed that, in a parallel way, had the mission of discovering the secrets of the functioning of both planes of the person: psychology and physiology.

However, despite the fact that both disciplines share the subject of study (the human being), each of them has specialized in different aspects of organisms . While physiology is dedicated to investigating how the different parts of our body work, psychology tries to understand the fundamentals of behaviour, conduct and mental processes of people.

As we said, both can be considered as two parts of a whole. They may appear to be independent, but they are closely related and can influence each other.

An example that can help us to clarify these ideas is the one in which we compare the mind and the brain. Both concepts are closely related and one cannot exist without the other; however, the former is part of the field of study of psychology, while physiology would be in charge of studying the functioning of the latter.

However, within the field of psychology we also find the study of how brain functioning is manifested and made visible through people’s behavior.

Differences between Physiology and Psychology

In order to go deeper into the differences between psychology and physiology, we will now see a brief description of the characteristics of these two disciplines .

1. What is psychology?

According to the American Psychological Association (APA) itself, psychology is the science that studies human mind and behavior , including both conscious and unconscious phenomena, feelings, and thoughts.

This discipline was born with the need to understand the role of mental functions and individual and social behaviour, while exploring the physiological and biological processes that underlie cognitive functions and behaviour, hence its close relationship with physiology.

Using the empirical method, researchers in psychology study behaviour and mental processes, which include perception, cognition, attention, emotions and affections, and personality , inferring causal relationships and correlations between different psychological and psychosocial variables.

While psychological knowledge is often applied to the assessment and treatment of problems or conditions of a mental nature, it is also directed at understanding and solving problems in various areas of human life, such as academic, work, sports and even media environments and forensic investigation.

Finally, there is a whole range of branches of psychology that are dedicated to the study of certain specific aspects of the mind, cognition and human behaviour. Some of them are:

  • Clinical psychology .
  • Cognitive and/or behavioral psychology.
  • Developmental psychology.
  • Forensic psychology.
  • Health psychology.
  • Neuropsychology .
  • Social psychology.

2. What is physiology?

On the other hand, physiology refers to that science that is dedicated to the scientific study of the mechanisms, functioning, and their interactions, of a living system . More specifically, it is a sub-discipline of biology that focuses on how organisms, organ systems, organs, cells and biomolecules carry out the chemical or physical functions that take place in a living system, regardless of whether it is human or not.

This would also be one of the main differences between psychology and physiology. While traditionally psychology has focused on the study of the human mind and behavior, physiology encompasses the study of the functioning of any living organism .

In this particular case, since we are making a comparison with psychology, we will focus on animal physiology, within which the study of the functioning of the human organism is included.

But not all is difference

As mentioned at the beginning of the article, although psychology and physiology have different specific objects of study, in matters of human research, the two fields are interrelated.

This relationship becomes manifest from the first moment we understand that the functioning of our body and our organism, starting with the brain, affects the functioning of our mind ; as well as the fact that certain psychological processes and mental disorders are capable of altering the development of the activity of our organism in what is known as somatization.

Such is the level of connection existing between these two fields of study that this led to the appearance of psychophysiology, currently known as cognitive neuroscience , a branch of study within psychology that is responsible for studying the physiological bases underlying psychological processes.

For example, while psychology is interested in the causes or factors that provoke the appearance of a phobia, psychophysiology focuses on the study of how the brain organs involved in the fear response, such as the amygdala, function in this situation, trying to relate the psychological and physiological aspects of a state of stress and anxiety such as phobias.