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
• Natural Selection / Evolution
• Adaptation
• Heredity / Genetics
• Nomothetic (studies the group)
Methodology
• Lab Experiments
• Correlation
• Twin research
• Naturalistic observations (Kettlewell)
• Reductionist
• Instincts / Sociobiology
• Comparative Psychology
Basic Assumptions
• 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.
Strengths
• 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
• Ethical Considerations
• Reliability and validity of research
Areas of Application
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Gender Role Development
Abnormal Psychology
IQ
Relationships
Medical Model
Stress Response (SRRS, stress immune syste
Limitations
• Experiments – Low Ecological Validity
• Humanism: too deterministic – little room for
free-will
• Doesn’t recognize cognitive processes
• Reductionist
• Bio psychological theories often overSimplify the huge complexity of
physical systems and their interaction
with the environment.