Psychology, 8th edition – Peter Gray & David F.
Bjorklund
Chapter 1: Background to the Study of Psychology
Psychology = the science of behaviour and the mind:
Behaviour = observable actions of a man or animal;
Mind = individual’s sensations, perceptions, memories, thoughts, dreams, motives, emotions
and other subjective experiences. Also refers to all of the unconscious knowledge and
operating rules that are built into or stored in the brain and that provide the foundation for
organizing behaviour and conscious experience.
Science = all attempts to answer questions through the systematic collection and logical
analysis of objectively observable data.
Data on behaviour is often used to make inferences about the mind.
Three fundamental ideas for psychology: A historical overview
Wilhelm Wundt opened the first university-based psychology laboratory in 1879. The roots of
psychology were developed by philosophers, physicists, physiologists and naturalists.
Three fundamental ideas:
1. Behaviour and mental experiences have physical causes that can be studied scientifically;
2. The way people behave, think, and feel is modified over time by their experiences in their
environment;
3. The body’s machinery, which produces behaviour and mental experiences, is a product of
evolution by natural selection.
The idea of physical causation of behaviour
Until the 18th century, Western philosophy was strongly bound to religion. The church maintained
that every human being consisted of 2 distinct but conjoined entities: a material body and an
immaterial soul - dualism. The body is part of the natural world and can therefore be studied
scientifically, but the soul is a supernatural entity that operates according to its own free will and not
according to natural laws and thus cannot be studied scientifically.
Descartes’ version of dualism: focus on the body
The essential ability that humans have but animals do not, is thought: conscious deliberation and
judgement.
Descartes sees the body as a complex machine that can also function independently of the soul, but
in order to be useful, thought must be responsive to sensory input and must be capable of directing
the body’s movements through the muscles. He believed that these signals moved through the body
via 'wires'.
Descartes thought that the soul, although not physical, acts on the body at a particular physical
location, a small organ (now known as the pineal body) buried between the two hemispheres
(halves) of the brain.
,Threadlike structures (nerves or neurons) bring sensory information by physical means into the brain,
where the soul receives the information and thinks about it. The soul then wills movements and
executes its will by triggering physical actions on the nerves, that, in turn, act on muscles.
Limitations:
How does a nonmaterial entity (soul) have a material effect?
How can the body follow a natural law and yet be moved by a soul that does not?
Why does brain damage affect the soul?
When does the soul come into existence?
Thomas Hobbes and the philosophy of materialism
Hobbes argued that the mind is a meaningless concept and that there is only matter and energy =
materialism. According to Hobbes, all human behavior, including seemingly voluntary choices, is the
result of physical processes that take place mainly in the brain. His ideas inspired the school of
empiricism.
Nineteenth-Century Physiology: Learning About the Machine
Physiology = the study of the body’s machinery.
Increased understanding of reflexes:
o Francois Magendie demonstrated that nerves entering the spinal cord contain two
separate pathways: one for carrying messages into the central nervous system from
the skin’s sensory receptors and one for carrying messages out to operate muscles.
o Through experiments with animals, scientists learned about neural connections that
underlie simple reflexes.
The concept of localization of function in the brain
, o Johannes Muller: nerves from different sense organs exite different parts of the
brain.
o Pierre Flourens: animal experiments showed that damage to different parts of the
brain produces different kinds of deficits in ability to move.
o Paul Broca: people with damage in a specific area in the left hemisphere lose the
ability to speak, but not other abilities.
The idea that the mind and behaviour are shaped by experience
Empiricism = human knowledge and thought derive ultimately from sensory experience (vision,
hearing, touch, etc.).
John Locke and John Stuart Mill argued that children are born without predispositions or peferences
on how they learn or develop (tabula rasa – blank slate); experience serves as the chalk that wrties
on and fills the slate. There is no ‘human nature’, other than the ability to adapt one’s own behaviour
to the demands of the environment – within the limits of the human body.
The empiricist concept of association by contiguity
Contiguity = closeness in space or time.
The law of association by contiguity = if a person experiences two environmental events (stimuli, or
sensations) at the same time or one right after the other (continguously), those two events will be
associated in the person’s mind, suhc that the thought of one event will, in the future, tend to elicit
the thought of the other.
Empiricists contended that even their own ideas could, in theory, be understood as amalgams of
elementary ideas that became linked together in their minds as a result of contiguities in their
experiecnes.
JSM called the above ‘mental chemistry’: complex ideas and thoughts are formed from combinations
of elementary ideas. E.g.: apple = round, red, crunchy, sour.
The nativist response to empiricism
Nativism = the most basic forms of human knowledge and the basic operating characteristics of the
mind, which provide the foundation for human nature, are native to the human mind – that is, are
inborn and do not have to be acquired from experiences. The mind must come with some internal
furnsishings in order for it to be furnished further through experience.
Immanuel Kant distinguished between a priori and a posteriori knowledge:
A priori: built into the human brain and does not have to be learned;
o E.g. ability to learn language.
A posteriori: gained from experience in the environment.
o E.g. learning specific words and grammar.
Without the first, one cannot acquire the second.
The idea that the machinery of behaviour and mind evolved through natural selection
Natural selection and the analysis of the functions of behaviour
,Darwin's fundamental idea was that living things evolve gradually, over generations, by a process of
natural selection. Individuals whose inherited characteristics are well adapted to their local
environment are more likely to survive and reproduce than other, less-well adapted individuals.
Innate characteristics of a species can be examined for the functions they serve in helping the
individuals to survive and reproduce. Same for behaviour: behaviour is adopted thay promote
survival and reproduction.
Darwin, thus, studies the functions of behaviour – the ways in which an organism’s behaviour helps it
to survive and reproduce.
Applying Darwin’s Ideas to Psychology
The basic forms of human emotional expressions are inherited, as are those of other animals, and
may have evolved because the ability to communicate one’s emotions or interntions improves one’s
chances of survival.
Darwin helped convince scholars that humans are part of the natural world and can be understood
through the methods of science.
The Scope of Psychology
Varieties of explanations in psychology and their application to sexual jealousy
Psychologists strive to explain mental experiences and behavior. To explain is to identify causes. A
person’s behaviour or mental experience can be examined at these complementary levels:
Neural (brain as cause);
Phyiological (internal chemical functions, such as hormones, as cause);
Genetic (genes as cause);
Evolutionary (natural selection as cause);
Learning (the individual’s prior experiences with the environment as cause);
Congitive (the individual’s knowledge or beliefs as cause);
Social (the influence of other people as cause);
Cultural (the culture in which te person develops as cause);
Developmental (age-related changes as cause).
To illustrate the different levels of analysis and research specialties in a real-world context, in the
following paragraphs the levels will be applied to the phenomenon of sexual jealousy.
Sexual jealousy is the set of emotions and behaviours that result when a person believes that his or
her relationship with a sexual partner or potential sexual partner is threatened by the partner’s
involvement with another person.
Explanations that focus on biological processes
Neural explanations: behavioural neuroscience explores how the nervous system produces a
particular behaviour or experience. Some behavioral neuroscientists study individual neurons
(nerve cells) or small groups of neurons to determine how their characteristics contribute to
particular psychological processes, such as learning. Others map out and study larger brain
regions and pathways that are directly involved in particular categories of behavior or
experience.
, o In one of the few studies to investigate neurological correlates of jealousy in humans,
male college students induced to feel jealous showed greater activation in the left
frontal cortex of their brains, as measured by electroencephalogram (EEG) recordings
toward their "sexually" desired partner (Harmon-Jones et al., 2009). Previous
research had shown that activation of the left frontal cortex is associated with
approach-motivation, typically associated with plea surable activities, whereas
activation in the right frontal cortex is associated with withdrawal-motivation,
typically corresponding to avoidance of negative stimuli. The primary motivational
state in jealouse may be one of approach, possibly aimed at preventing a threatening
liaison or at re-establishing the primary relationship.
Physiological explanations: biopsychology studies the ways hormones and drugs act on the
brain to alter behaviour and experience.
o The hormone estadriol is related to the intensity of jealous feelings in young women,
especially during the period of increased fertility in their menstruationcycle.
Genetic explanations: behavioural genetics attempts to explain psychological differences
among individuals in terms of differences in their genes.
o E.g.: modifying genes in animals to observe the effect on behaviour, or identifying
genes that contribute to a characteristic by comparing the DNA with people who do
not show this characteristic.
o Research could be done with regard to sexual jealousy in identical vs fraternal twins
to determine possible genetic causes.
Evolutionary explanations: evolutionary psychology aims to explain how or why universal
human characteristics (behaviours and mental experiences) came about in the course of
evolution.
o Research supports the view that jealousy functions to promote long-term mating
bonds. Jealousy seems to have the function to drive off or discourage individuals that
would lure away their mate.
Explanations that focus on environmental experiences, knowledge and development
Learning explanations: learning psychology aims to explain behaviour in terms of learning.
All forms of human behaviour and mental experience are modifiable by learning; they can be
influenced by prior experiences.
o When jealous behaviour is effective, it will increase in frequency.
Cognitive explanations: cognitive psychology investigates the types of information in the
mind (cognition – includes thoughts, beliefs, and all forms of memories), that underlie some
action or behaviour. Also researches how information is stored in the brain (memories and
memory). Experience leads to change in knowledge or beliefs, which in turn leads to change
in behaviour.
o Jealousy can be studied by asking people to recollect episodes of jealousy and
describe the thoughts that went through their minds, the emotions they felt, and the
action they took. Various thoughts can lead to different behaviours.
Social explanations: social psychology aims to explain mental experiences and behaviour by
identifying how they are influenced by other people or by one’s beliefs about other people.
o Jealousy can be studied by focusing on the norms and convictions concerning
romance, mating and jealousy that surround and influence the jealous person. Are
the beloved’s flirtations with another wihtin or outside the realm of what is
considered acceptable by other dating or married couples? Etc.
, Cultural explanations: cultural psychology explains mental experiences and behaviour in
terms of a person's cultural background.
o A cultural psychologist would point to significant cultural differnces in romantic and
sexual morals.
Developmental explanations: developmental psychology documents and describes the
typical age differnces in how people feel, think, and act. Developmental psychologists may
describe the sequence of changes that occur from infancy to adulthood, for any given type of
behaviour or mental capacity. Developmental psychologists are particularly interested in
understanding how experiences at any given stage of development can influence behaviour
at later stages.
o People who develop secure relationships with their parents and friends in childhood
also tend, later on, to develop secure relationships with romantic partners, relatively
untroubled by jealousy.
Chapter 2: Methods of Psychology
Observations, theories, and hypotheses
Observation = an objective statement that reasonable observers agree is true.
Theory = An idea, or a conceptual model, that is designed to explain existing observations and make
predictions about new observations that might be discovered.
Hypothesis = Prediction about new observations that is made from a theory.
Cycle of science: observations lead to theories, which lead to hypotheses, which are tested with
experiments or other research studies; these in turn lead to new observations, etc.
Theory without observations is merely speculation, and observations without theory are
simply data without explanations.
The lessons
Three lessons about scientific research:
1. The value of skepticism: people are fascinated by extraordinary claims and often act as
though they want to believe them. The simpler an explanation is, the better it tends to be
(parsimony or Occam’s razor). Ideally, a scientist always tries to disprove theories, even those
that are his or her own.
2. The value of careful observations under controlled conditions: careful observation under
controlled conditions is a hallmark of the scientific method.
3. The problem of observer-expectancy effects: Observers may unintentionally communicate to
subjects their expectations, and the subjects may respond by doing just what the researcher
expects. Bias and expectancy effects should be avoided.
Types of Research Strategies
Research strategies can be categorized as varying along three dimensions:
1. The research design: three basic types: experiments, correlational studies, and descriptive
studies.
2. The setting in which the study is conducted, of which there are two basic types: field and
laboratory.
3. The data collection method: two types: self-report and observation.
,Research designs
Experiments
An experiment is the most direct and conclusive approach to testing a hypothesis about a cause-
effect relationship between two variables. A variable is anything that can change or assume different
values. In describing an experiment, the variable that is hypothesized to cause some effect on
another variable is called the independent variable, and the variable that is hypothesized to be
affected is called the dependent variable. The aim of any experiment is to learn whether and how
the dependent variable is affected by (depends on) the independent variable.
More specifically, an experiment can be defined as a procedure in which a researcher systematically
manipulates (varies) one or more independent variables and looks for changes in one or more
dependent variables, while keeping all other variables constant. If all other variables are kept
constant and only the independent variable is changed, then the experimenter can reasonably
conclude that any change observed in the dependent variable is caused by the change in the
independent variable.
In some experiments, called within-subject experiments (or sometimes repeated-measures
experiments), each subject is tested in each of the different conditions of the independent variable
(that is, the subject is repeatedly tested). In other experiments, called between-groups experiments
(or sometimes, between subjects experiments), there is a separate group of subjects for each
different condition of the independent variable.
Correlational studies
Correlational study = a study in which the researcher does not manipulate any variable, but observes
or measures two or more already existing dependent variables to find relationships between them.
Correlational studies can identify relationships between variables, which allow us to make
predictions about one variable based on knowledge of another; but such studies do not tell us in any
direct way whether change in one variable is the cause of change in another.
Cause and effect cannot be determined from a correlational study. Third variable that was not
measured can be of influence as well, and the measured variables can have influence each other
from A to B or from B to A.
Descriptive studies
Descriptive study = to describe the behaviour of an individual or set of individuals without assessing
relationships between different variables.
Research settings
Setting is laboratory or field:
Laboratory study = any research study in which the subjects are brought to a specially
designated area that has been set up to facilitate the researcher’s collection of data or
control over environmental conditions. Researcher has control over what experiences the
subject has.
Field study = any research study conducted in a setting where the researcher does not have
control over the subjects’ experiences.
Data-collection methods
, Two broad categories:
Self-report methods = people are asked to rate or describe their own behaviour or mental
stat in some way.
o Might be done through a written questionnaire or an interview.
o Introspection = a form of self-report: the personal observations of one’s thoughts,
perceptions and feelings. Subjectivity of this method made it target of criticism.
Modern methods for measuring neural activity make the introspections more
‘observable’.
Observational methods = all procedures by which researchers observe and record the
behaviour of interest rather than relying on subjects’ self-reports.
o Test = subcategory where researcher presents problems, tasks or situations to which
the subject responds.
o Naturalistic observation = subcategory where the researcher avoids interfering wth
the subjects’s behaviour.
If subject has knowledge of them being watched (obtrustive observation),
this might affect their behaviour (= Hawthorne effect).
Habituation (decline in response when a stimulus is repeatedly or
continuously present) may minimize Hawthorne effects since
subjects may habituate to the presence of the researcher overtime.
Statistical Methods in Psychology
Statistical procedures can be divided into two categories:
1. Descriptive statistics: used to summarize sets of data.
2. Inferential statistics: help researchers decide how confident they can be in judging whether
the results observed are due to chance.
Descriptive statistics
Describing a set of scores
Summarize measurements by calculating the mean or the median (and the variability):
Mean = the arithemetic average
Median = center score
Variability = the degree to which the numbers in the set differ from one another and from
their mean.
o If numbers cluster close together, variability is low. If numbers differ widely from the
mean, variability is high.
o Standard deviation = common measure of variability, calculated by a certain
formula.
Describing a correlation
Correlational studies examine two or more variables to determine whether or not a nonrandom
relationship exists between them.
Correlation coefficient shows strength and direction of the relationship. Calculated by a formula that
produces a result from -1.00 to +1.00.
Thus, correlation can be positive or negative:
