Biological Psychology

by Saul McLeod, published 2007

Biology is defined as the study of life (from the Greek bios meaning ‘life’ and logos meaning ‘study’). 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 and the genetic, can help explain human behavior.

History of The Biological Approach

* The Voyage of the Beagle (1805 - 1836) - Darwin formulated his theory of natural selection through observing animals while travelling the world.

* Phineas Gage (1848) brain injury case study provides neuroscience with significant information regarding the working of the brain.

* Darwin (1859) publishes "On the Origin of Species by Means of Natural Selection". 1,250 copies were printed, most of which sold the first day.

* Jane Goodall (1957) began her study of primates in Africa, discovering that chimps have behaviors similar to all the human cultures on the planet.

* Edward Wilson (1975) published his book, "Sociobiology" which brought together evolutionary perspective to the psychology.

* The birth of Evolutionary Psychology begins with the publication of an essay "The Psychological Foundations of Culture" by Tooby and Cosmides.

Biological Approach Summary

Key Features	Methodology
Natural Selection / Evolution Adaptation Heredity / Genetics Nomothetic (studies the group) Reductionist Instincts / Sociobiology Comparative Psychology	Lab Experiments Correlation Twin research Naturalistic observations (Kettlewell) Ethical Considerations Reliability and validity of research
Basic Assumptions	Areas of Application
Psychology should be seen as a science, to be studied in a scientific manner (usually in a laboratory). 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.	Gender Role Development Abnormal Psychology IQ Relationships Medical Model Stress Response (SRRS, stress immune system)
Strengths	Limitations
Very Scientific Highly application to other areas: Biology + Cog = Evolutionary Psy Helped develop comparative psychology Strong counter argument to the nurture side of the debate Many empirical studies to support theories	Experiments – Low Ecological Validity Humanism: too deterministic – little room for free-will Doesn’t recognize cognitive processes Reductionist Bio psychological theories often over-simplify the huge complexity of physical systems and their interaction with the environment.

Further Information

Listen to a MIT undergraduate lecture on Love and Evolution.

Listen to a MIT undergraduate lecture on The Brain.

BBC Radio 4: The influence of evolutionary theory, phrenology and a hole in Phineas Gage's head.

BBC Radio 4: Dr Geoff Bunn discusses the impact of neurology on how we understand ourselves today.

BBC Radio 4: Mind Myths.

How to cite this article: McLeod, S. A. (2007). Simply Psychology; . Retrieved , from