Chapter 1: Introduction to Psychological Science
Major themes of psychological science
•Psychological science- the study of mind (mental activity, such as thoughts and feelings),
brain (where the biological processes occur that give rise to the mind) and behaviour (the
wide variety of actions that occur in organisms from ants to humans)
•4 major themes that have defined and are defining psychology-
oResearch on mind, brain and behaviour has accumulated over time to produce the
principles of psychological science.
oA new biological revolution has enabled us to better understand the human mind and
human behaviour. Three developments have contributed to this:
An increased understanding of brain chemistry
Much progress has been made in identifying neurotransmitters (chemicals
that communicate messages through nerve cells) and their functions. It has
been discovered that hundreds of substances (including neurotransmitters)
influence mental activity and behaviour.
An increased understanding of the influence of genetic processes
Scientists have been able to map out the human genome- the basic genetic
code or blueprint for the human body.
Various techniques have also been developed to study the link between genes
The development of methods to observe the brain in action- brain imaging
Researchers have only been able to do this since the late 1980s. This has
enabled them to better understand how the brain produces human perceptual
experience, for example.
Answer to the century-old debate over whether psychological processes are
located in specific parts of the brain or distributed throughout- We now know
that there is some localization of function, but that many different regions of
the brain work together to produce behaviour and mental activity.
oThe discovery that the mind is adaptive, and has been shaped by evolution
Evolutionary theory- emphasizes that the brain is an organ that has evolved
over millions of years to solve problems related to survival and reproduction.
Further, natural selection (Darwin’s theory) ensured that only our ancestors
with adaptations (the physical characteristics, skills, or abilities that increase
the chances of survival and reproduction) passed on their genes.
Adaptive behaviours have been built into the brain (and body), and it has
evolved specialized structures to deal with adaptive problems (e.g. the capacity
to see well, recognize dangerous objects etc.). However, many of our current
behaviours (e.g. reading books, driving cars, using computers etc.) don’t
reflect our evolutionary heritage and have only recently become part of human
experience. However, these behaviours can be considered by-products of
adaptive solutions to earlier adaptive problems.
Culture (the beliefs, values, rules, and customs that exist within a group of
people who share a common language and environment and that are
transmitted through learning from one generation to the next) also provides
Although biological evolution took place over millions of years, cultural
evolution has only been over the past several thousand years.
- For example, researchers have found distinct differences between the
worldviews of typical Easterners and Westerners. Social psychologist Richard
Nisbett argued that these cultural differences date back to ancient Greek and
Chinese societies. Cultural psychologists still find that Westerners tend to be
independent and autonomous, stressing their individuality, while Easterners
are more interdependent, and see themselves more as part of a collective.
•Psychological science can be studied on many levels of analysis.
oPsychologists often collaborate with researchers from other sciences, including
biology, computer science, physics, anthropology and sociology
oPsychologists study three basic categories of behaviour and mental life: social,
individual, and biological.
Social analysis can be divided into cultural and interpersonal analysis
Individual analysis can be broken down into the analysis of individual
differences, perception and cognition, and behaviour
Biological analysis involves brain systems, neurochemical and genetic analysis
The intellectual origins of psychology
•Nature vs. nurture debate
oBasically, whether psychological characteristics are due to nature (biologically
innate) or nurture (acquired through education, experience, and culture
o It is now recognized that both are important, but recent advances in scientific
knowledge allow psychological scientists to specify when either nature or nurture is
important, and how they interact.
oFor example, until the 1950s, it was believed that schizophrenia (a disorder in which
people have unusual thoughts or experience unusual sensations) and bipolar
disorder (characterized by dramatic mood swings from depression to euphoria)
resulted from bad parenting and other environmental circumstances (nurture).
However, in the 50s and 60s, drugs were discovered that alleviated symptoms, and
more recent research shows that these conditions are heritable.
oPsychological scientists now believe that many mental disorders are equally a result
of nurture and nature. Another example is post-traumatic stress disorder (PTSD).
PTSD is a result of traumatic experiences, but research shows that some people are
genetically predisposed to PTSD, indicating that nurture can activate nurture.
oAlso, social environment plays an important role in whether treatment is successful
oConsiders whether the mind and body are separate and distinct, or whether the mind
is simply the subjective experience of the physical brain
oFor most of human history the mind and body have been believed to be separate
entities, with the mind controlling the body. This is partly because of theological
beliefs that a divine and immortal soul is what separates humans from animals
o Descartes promoted dualism- the belief that the mind and body are separate, yet
He believed that the body was nothing more than an organic machine,
governed by reflex, and that many mental functions (like memory and
imagination) were the result of bodily functions. This was different from past
dualist theories, which held that all mental states were separate from bodily
However, he concluded that the rational mind, which controlled volitional
action, was divine and separate from the body.
He also suggested that the body could also affect the mind. For example,
passions like love, hate, and sadness arose from the body and influenced
•Charles Darwin’s evolutionary theory
oAn implication of his theory of natural selection was that individual differences
provide the bases of evolutionary development.
oHis cousin Francis Galton proposed that some differences were psychological in
nature, and that they could be measured and tested, resulting in the mental testing
The scientific origins of philosophy
•John Stuart Mill published System of Logic, in which he argued that psychology should leave
the realm of speculation and philosophy. Further, he argued that only through science would
the processes of the mind be understood.
•This led to a growing emphasis on the use of careful scientific observation to study mental
activity during the 1800s.
oWilhelm Wundt established the first psychology laboratory and institute in
Germany. He is widely considered to be the father of experimental psychology as an
academic discipline, and trained many of the early psychologists, including Edward
Wundt developed the method of introspection- a systematic examination of
subjective mental experiences that requires people to inspect and report on the
content of their thoughts
oEdward Tichener used methods such as introspection to develop a new school of
thought, structuralism- an approach to psychology based on the idea that conscious
experience can be broken down into its basic underlying components or elements
He argued that one could take a stimulus such as a musical tone, and by
introspection analyze its quality, intensity, duration, and clarity. Wundt disagreed but
Tichener used this method throughout his career.
Much progress has been made in identifying neurotransmitters (chemicals that communicate messages through nerve cells) and their functions. It has been discovered that hundreds of substances (including neurotransmitters) influence mental activity and behaviour. an increased understanding of the influence of genetic processes. Scientists have been able to map out the human genome- the basic genetic code or blueprint for the human body. Various techniques have also been developed to study the link between genes and behaviour. the development of methods to observe the brain in action- brain imaging. Researchers have only been able to do this since the late 1980s. This has enabled them to better understand how the brain produces human perceptual experience, for example. evolutionary theory- emphasizes that the brain is an organ that has evolved over millions of years to solve problems related to survival and reproduction.