Psychology is a science of behaviour, including both overt and covert activities. Biology studies the activities of all living beings, and its aim is to study how they grow, reproduce, and continue the life processes. Behaviour of man is the result of his interaction with the environment. So, the behaviour cannot be systematically studied without the knowledge of biological principles.

Biological sciences are related to physiology, which studies the functions of living organisms and biochemical basis of behavior. They are also related to neurology, which studies the brain processes, and the nervous system.

There are new branches called ‘Physiological Psychology’ and ‘Neuropsychology’. Physiologists study the functions of internal bodily organs, activities of glands, and the nature of respiration, blood circulation, and digestion. All these activities are related to behaviors, as biological and psychological systems are interdependent.

Further, the biological sciences have relations with ‘Genetics’ those studies the hereditary processes, and ‘Embryology’, which studies the growth and development of the organism before, birth.


Though psychology has close relationship with biology, yet both differ in terms of their emphasis. The primary focus of a biologist is to study the structures and functions of the bodily organs. Psychology emphasizes the study of mental processes and behaviors as they are shaped by the biological structures and functions. In spite of some overlapping concern, each discipline maintains its unique emphasis.