Foundations (10-14%)
History
➢ John Locke and empiricism
○ Philosopher who extended Descartes’s application of natural laws to all things: believing that even
the mind is under the control of such laws
■ Descarte: Fluid in the brain flows through nerves, causing movement so reflexes aren’t
controlled
○ Locke’s school of thought is known as empiricism
■ The view that knowledge comes from experience via the senses, and science flourishes
through observation and experiment
■ The roots of psychology can be traced back to the philosophy of Empiricism:
emphasizing the role of experience and evidence, especially sensory perception, in the
formation of ideas, while discounting the notion of innate ideas
○ In his book, Essay Concerning Human Understanding, Locke proposed that humans are born
knowing nothing; Locke used the term tabula rasa (Latin for “blank slate”) to describe the mind of
an infant
○ Locke felt that all knowledge must derive from experience
○ Locke emphasized nurture over nature as the greater influence on development
➢ Thomas Hobbes and behaviorism
○ Thomas Hobbes (1588–1679) believed that the idea of a soul or spirit, or even of a mind, is
meaningless
○ Hobbes’s philosophy is known as materialism, which is the belief that the only things that exist are
matter and energy and what we experience as consciousness is simply a by-product of the
machinery of the brain
○ Hobbes greatly influenced behaviorism
■ The view that psychology should be an objective science that studies behavior without
reference to mental processes
■ This learning theory states that behaviors are learned from the environment, and says that
innate or inherited factors have very little influence on behavior
➢ Charles Darwin and evolutionary theory
○ In On the Origin of Species (1859), Charles Darwin (1809–1882) proposed a theory of natural
selection, according to which all creatures have evolved into their present state over long periods
of time
○ This evolution occurs because there exists naturally occurring variation among individuals in a
species, and the individuals that are best adapted to the environment are more likely to survive and
then reproduce—and are likely to produce more successful offspring
○ Evolutionary theory affected psychology by providing a way to explain differences between
, species and justifying the use of animals as a means to study the roots of human behavior ○
Behavior evolves just like physiology: both function to help individuals survive
➢ Edward Titchener and introspection
○ Edward Titchener (1867–1927) was a student in Wundt’s laboratory and was one of the first to
bring the science of psychology to the United States
○ Titchener sought to identify the smallest possible elements of the mind, theorizing that
understanding all of the parts would lead to the understanding of the greater structure of the mind ○
Which are illuminated through interviews with a subject describing his or her conscious experience,
this is known as introspection
○ Introspection is just looking within oneself to explore the elemental structure of the human mind ➢
Wilhelm Wundt and structuralism
○ Many credit Wilhelm Wundt (1832–1920) as the founder of the science of psychology. ○ Wundt
was trained in physiology and hoped to apply the methods that he used to study the body to the study
of the mind
○ Structuralism was founded by Wilhelm Wundt, who used controlled methods, such as
introspection, to break down consciousness to its basic elements without sacrificing any of the
properties of the whole
■ Structuralism was the approach and introspection was the methodology
○ Structuralism entails looking for patterns in thought
➢ William James and functionalism
○ William James (1842–1910), an American psychologist, opposed the structuralist approach ■
Examined how the structures identified by Wundt function in our lives
■ Structures of consciousness must have a function such as smelling and thinking
○ Argued that what is important is the function of the mind, such as how to solve a complex problem ○
James, influenced by Darwin, believed that the important thing to understand is how the mind fulfills
its purpose
○ This function-oriented approach is appropriately called functionalism
➢ Mary Whiton Calkins, Dorothea Dix, G. Stanley Hall, Margaret Floy Washburn
○ Mary Whiton Calkins: first female graduate student in psychology, but she was denied a PhD
because of her gender; she outscored all of the male students in her qualifying exams
○ Dorothea Dix: reformed mental institutions in the U.S.
○ G. Stanley Hall: first president the American Psychological Association, formed in 1892 ○
Margaret Floy Washburn: first female PhD in psychology and served as the second female
president of the American Psychological Association
Approaches
➢ Behavioral genetics
○ Behavioral genetics is the field of psychology that explores how particular behaviors may be
attributed to genetics
, ○ This perspective takes into account biological predispositions as well as the extent of influence
that the environment had
○ A person studying behavioral genetics might investigate to what extent risk-taking behavior in
adolescents is attributable to genetics
➢ Behaviorism
○ Behaviorism posits that psychology is the study of observable behavior and that the mind or
mental events are unimportant as they cannot be observed
○ Classical conditioning, first identified by Ivan Pavlov (1849–1936), was one of the behaviorists’
most important early findings; it is defined as a form of learning in which learning in which a
behavior comes to be elicited by a formerly neutral stimulus
■ John Watson (1878–1958) and his assistant Rosalie Rayner applied classical conditioning
to humans in the famed Little Albert experiment: they made loud sounds behind a
9-month-old whenever he would touch something white and furry, and he was afraid of
everything white and furry afterwards
○ B. F. Skinner (1904–1990), through the development of Skinner Box, described operant
conditioning, in which a subject learns to associate a behavior with an environmental outcome ■ A
Skinner box is a device used to record an animal's behavior in a compressed time frame in which it will
be rewarded or punished for engaging in certain behaviors
○ Behaviorism no longer prevailing approach in psychology but behavioral principles still used in
behavior modification: techniques in which psychological problems are considered to be the
product of learned habits and can be unlearned by using behavioral methods
➢ Biological
○ View genes, chemicals and body types as the determinant of personality
○ Genetics play a role in temperament: emotional style and characteristics that define how a person
deals with the world
➢ Biopsychosocial
○ Emphasizes the need to investigate the interaction of biological, psychological, and social factors
as contributing to a behavior or a mental process
➢ Cognitive/cognitive-behavioral
○ Cognitive psychology is an approach rooted in the idea that to understand people’s behavior, we
must first understand how they think
○ Cognitive psychology concerns itself with thinking, memory, and internal thought processes ○ This
approach combines the structuralist approach of looking at the subcomponents of thought and
functionalist approach of understanding the purpose of thought
○ Replaced the purely behavioral approach as the predominant psychological method used in U.S.
➢ Evolutionary
○ The study of behaviors and mental processes that are inherited from ancestors and how the
principles natural selection and genes present
, ○ Draws from Darwinian theories of natural selection and evolution
○ For example, fear is an adaptive evolutionary response and without fear our survival would be
jeopardized
➢ Gestalt
○ School of thought that looks at the human mind and behavior as a whole
○ Core belief is holism, or that the whole is greater than the sum of its parts
○ When trying to make sense of the world around us, we do not simply focus on every small
component; instead, our minds tend to perceive objects as part of a greater whole and as elements
of more complex systems
➢ Humanistic
○ Humanistic approach is rooted in the philosophical tradition of studying the roles of
consciousness, free will, and awareness of the human condition
○ Humanistic psychologists emphasize personal values and goals and how they influence behavior ○
Abraham Maslow (1908–1970) proposed the idea of self-actualization: we have a hierarchy of needs;
you can’t achieve the top level, self actualization, unless the previous levels have been achieved
because lower needs dominate an individual’s motivation as long as they are unsatisfied; from bottom
to top the levels are physiological needs, safety, belonging, self-esteem, self-actualization
○ Carl Rogers (1902–1987) believed in unconditional positive regard: people will naturally strive for
self actualization and high self-esteem, unless society taints them
➢ Psychodynamic/psychoanalytic
○ Developed by Freud (1856–1939) who believed that the id, superego and ego, fought for
dominance in an individual’s unconscious and thus compose their personality
■ Id (instincts): the primitive and instinctual part of the mind that contains sexual and
aggressive drives and hidden memories; exists in the unconscious mind
■ Ego (reality): reality principle/negotiator between desires of the id and limitations of the
environment; mediate between id and superego; exists in party conscious and partly
unconscious
■ Superego (morality): control the id's impulses, especially those which society forbids,
such as sex and aggression and persuades the ego to turn to moralistic goals rather than
realistic ones and to strive for perfection; operates on conscious and unconscious level
○ Believed innate drives for sex and aggression are the primary motives for our behavior and
personalities
➢ Sociocultural
○ Belief that the environment a person lives in has a great deal to do with how the person behaves
and how others perceive that behavior
○ Cultural values vary from society to society and must be taken into account if one wishes to
understand, predict, or control behavior
,Domains
➢ Biological
○ A question that concerns the effect of drugs on behavior refers to the biological domain
➢ Clinical
○ A question that considers treatments for someone addicted to drugs deals with the clinical domain
➢ Cognitive
○ What thoughts might someone entertain to justify their drug use?
➢ Counseling
○ How might a school counselor talk to a student about drugs?
➢ Developmental
○ At what ages might someone be more susceptible to peer pressure?
➢ Educational
○ How effective are school-based programs?
➢ Experimental
○ Dealing with experiments
➢ Industrial-organizational
○ Dealing with workplaces
➢ Personality
○ Dealing with personality
, ➢ Positive
○ Focuses on positive aspects and strengths of human behavior
➢ Psychometric
○ Dealing with how to measure things in psychology
➢ Social
○ A question about relationships between drug users and their families refers to the social domain
Methods
➢ Causation vs. correlation
○ Correlation is a relationship between two variables; when one variable changes, the other variable
also changes
○ Causation is when there is a real-world explanation for why this is logically happening; it implies a
cause and effect
➢ Descriptive statistics
○ Correlation coefficient
■ The correlation coefficient is a numerical value that indicates the degree and direction of
the relationship between two variables
■ Correlation coefficients range from +1.00 to –1.00; the sign (+ or –) indicates the
direction of the correlation, and the number (0 to + or –1.00) indicates the strength of the
relationship
○ Frequency distribution (normal, bimodal, positive or negative skew)
■ In a perfectly normal distribution, the mean, median, and mode are identical
■ If two numbers both have the greatest frequency (mode), the distribution is bimodal ■
A positive skew means that most values are on the lower end, but there are some
exceptionally large values
■ A negative skew means the opposite: most values are on the higher end, but there are
some exceptionally small values
○ Measures of central tendency
■ The mean is the arithmetic average of a set of numbers
■ The mode is the most frequently occurring value in the data set
■ The median is the number that falls exactly in the middle of a distribution of numbers ■
These statistics can be represented by a normal curve
○ Variation (range, standard deviation)
, ■ The range is simply the largest number minus the smallest number
■ The standard deviation determines the height and width of the graph
● When the standard deviation is large, the curve is short and wide
● When the standard deviation is small, the curve is tall and narrow
● In a typical distribution of numbers, about 68 percent of all scores are within one
standard deviation above or below the mean, and about 95 percent of all scores
are within two standard deviations above or below the mean
○ So, for example, IQ is typically said to have a mean of 100 and a
standard deviation of 15, so a person with a score of 115 is one
standard deviation above the mean
● Math questions about normal distributions can appear on the test, but because
skewed distributions do not all share the same mathematical properties,
questions about percentages and these distributions are often trick questions
● In skewed distributions, the median is a better indicator of central tendency than
the mean
➢ Groups
○ Control vs. experimental
■ The group receiving or reacting to the independent variable is the experimental group; the
control group does not receive the independent variable but should be kept identical in all
other respects
, ■ Using two groups allows for a comparison to be made and causation to be determined ○
Random assignment
■ Subjects are randomly assigned into both the experimental and control groups
■ Random assignment is done to ensure that each group has minimal differences
○ Random selection
■ Random sampling/selection is a way of ensuring maximum representativeness: the degree
to which a sample reflects the diverse characteristics of the population that is being
studied
● Unintentional sampling bias occurred during the 1948 U.S. Presidential
Election: a survey was conducted by randomly calling households and asking
them whom they intended to vote for, Harry Truman or Thomas Dewey, and
based on this phone survey, Dewey was projected to win but the results of the
election proved otherwise, as Truman was re-elected
● In 1948, having a telephone was not such a common thing, and households that
had them were generally wealthier; as a result, the “random” selection of
telephone numbers was not a representative sample because many people did not
have telephone numbers
■ Types of sampling bias
● The bias of selection from a specific real area occurs when people are selected in a
physical space; for example, if you wanted to survey college students on
whether or not they like their football team, you could stand on the quad and
survey the first 100 people that walk by; however, this is not completely random
because people who don’t have class at that time are unlikely to be represented
● Self-selection bias occurs when the people being studied have some control over
whether or not to participate; for example, an Internet survey might elicit
responses only from people who are highly opinionated and motivated to
complete the survey
● Pre-screening or advertising bias occurs often in medical research; how
volunteers are screened or where advertising is placed might skew the sample;
for example, if a researcher wanted to prove that a certain treatment helps people
to stop smoking, the mere act of advertising for people who “want to quit
smoking” might provide only a sample of people who are already highly
motivated to quit and might have done so without the treatment
● Healthy user bias occurs when the study population tends to be in better shape
than the general population
➢ Inferential statistics
○ Purpose is to determine whether or not findings can be applied to the larger population from which
, the sample was selected
○ The extent to which the sample differs from the population is known as sampling error ○
Psychologists typically want to be able to generalize the results of the experiment to a larger group of
people so it is important that the sample reflects the characteristics of the population as a whole and if
it does, then the sample is referred to as being representative
➢ Inter-rater reliability
○ It is also important that the study have reliability, which is whether or not the same results appear if
the experiment is repeated under similar conditions
○ A related concept is inter-rater reliability, the degree to which different raters agree on their
observations of the same data
➢ Operational definitions
○ The conceptual definition is the theory or issue being studied, the operational definition refers to
the way in which that theory or issue will be directly observed or measured in the study ○ In a study
on the effects of adolescent substance abuse, the way in which taking drugs affects adolescent
behavior is the conceptual definition, while the number of recorded days the student is absent from
school due to excessive use of substances is the operational definition
○ Operational definitions have to be internally and externally valid
➢ Study types
○ Case study
■ Case studies are intensive psychological studies of a single individual
■ These studies are conducted under the assumption that an in-depth understanding of
single cases will allow for general conclusions about other similar cases
■ Multiple case studies on similar cases are combined to draw inferences about issues ■
The danger of generalizing from the outcomes of case studies is that the individuals
studied may be atypical of the larger population, so researchers try to ensure that their
studies are generalizable—that is, applicable to similar circumstances because of the
predictable outcomes of repeated tests
■ Disadvantage because cannot assume cause & effect
○ Correlational
■ Involves assessing the degree of association between two or more variables that occurs
naturally; if the characteristics under consideration are related, they are correlated ■
Researchers do not directly manipulate variables but rather observe naturally occurring
differences
■ It is important to note that correlation does not prove causation; correlation simply shows
the strength of the relationship among variables
● For example, poor school performance may be correlated with lack of sleep;
however, we do not know if lack of sleep caused the poor performance, or if the
poor school performance caused the lack of sleep, or if some other unidentified
, factor influenced them both
■ One way to gather information for correlational studies is through surveys. Using either
questionnaires or interviews, one can accumulate a tremendous amount of data and study
relationships among variables.
● For example, survey studies might examine the relationship between
socioeconomic status and educational levels.
■ Correlational studies can be preferred to experiments because they are cheaper, consume
less time, easier to conduct, and some concepts can't be ethically studied in experiments ●
For example, you may want to study how child abuse affects self-efficacy in adulthood, but
no one will allow you to randomly assign half of your baby
participants to the child abuse condition
■ It can identify relationship between two variables but not cause & effect
○ Cross-sectional
■ Cross-sectional studies are designed to test a wide array of subjects from different
backgrounds to increase generalizability
■ It does not involve manipulating variables and happens at a single point in time ■ Allows
researchers to look at numerous characteristics at once (age, income, gender, etc.) ■ Done
because don’t have to wait a long time with the same subjects and can simply use people
from other gaps; the generational gap may cause differences however
○ Experimental
■ An experiment is an investigation seeking to understand relations of cause and effect ●
The experimenter changes a variable (cause) and measures how it changes
another variable (effect)
○ The manipulated variable is called the independent variable and the
dependent variable is what is measured
● At the same time, the investigator tries to hold all other variables constant so she
can attribute any changes to the manipulation
■ Subjects are randomly assigned into both the experimental and control group to ensure
that each group has minimal differences using single or double-blind method
● Single-blind design means that the subjects do not know whether they are in the
control or experimental group and in a double-blind design, neither the subjects
nor the researcher knows who is in the two groups
○ Double-blind studies are designed so that the experimenter does not
inadvertently change the responses of the subject, such as by using a
different tone of voice with members of the control group than the
experimental group
■ In some double-blind, the control group is given a placebo
which makes the control group to believe they’re the
History
➢ John Locke and empiricism
○ Philosopher who extended Descartes’s application of natural laws to all things: believing that even
the mind is under the control of such laws
■ Descarte: Fluid in the brain flows through nerves, causing movement so reflexes aren’t
controlled
○ Locke’s school of thought is known as empiricism
■ The view that knowledge comes from experience via the senses, and science flourishes
through observation and experiment
■ The roots of psychology can be traced back to the philosophy of Empiricism:
emphasizing the role of experience and evidence, especially sensory perception, in the
formation of ideas, while discounting the notion of innate ideas
○ In his book, Essay Concerning Human Understanding, Locke proposed that humans are born
knowing nothing; Locke used the term tabula rasa (Latin for “blank slate”) to describe the mind of
an infant
○ Locke felt that all knowledge must derive from experience
○ Locke emphasized nurture over nature as the greater influence on development
➢ Thomas Hobbes and behaviorism
○ Thomas Hobbes (1588–1679) believed that the idea of a soul or spirit, or even of a mind, is
meaningless
○ Hobbes’s philosophy is known as materialism, which is the belief that the only things that exist are
matter and energy and what we experience as consciousness is simply a by-product of the
machinery of the brain
○ Hobbes greatly influenced behaviorism
■ The view that psychology should be an objective science that studies behavior without
reference to mental processes
■ This learning theory states that behaviors are learned from the environment, and says that
innate or inherited factors have very little influence on behavior
➢ Charles Darwin and evolutionary theory
○ In On the Origin of Species (1859), Charles Darwin (1809–1882) proposed a theory of natural
selection, according to which all creatures have evolved into their present state over long periods
of time
○ This evolution occurs because there exists naturally occurring variation among individuals in a
species, and the individuals that are best adapted to the environment are more likely to survive and
then reproduce—and are likely to produce more successful offspring
○ Evolutionary theory affected psychology by providing a way to explain differences between
, species and justifying the use of animals as a means to study the roots of human behavior ○
Behavior evolves just like physiology: both function to help individuals survive
➢ Edward Titchener and introspection
○ Edward Titchener (1867–1927) was a student in Wundt’s laboratory and was one of the first to
bring the science of psychology to the United States
○ Titchener sought to identify the smallest possible elements of the mind, theorizing that
understanding all of the parts would lead to the understanding of the greater structure of the mind ○
Which are illuminated through interviews with a subject describing his or her conscious experience,
this is known as introspection
○ Introspection is just looking within oneself to explore the elemental structure of the human mind ➢
Wilhelm Wundt and structuralism
○ Many credit Wilhelm Wundt (1832–1920) as the founder of the science of psychology. ○ Wundt
was trained in physiology and hoped to apply the methods that he used to study the body to the study
of the mind
○ Structuralism was founded by Wilhelm Wundt, who used controlled methods, such as
introspection, to break down consciousness to its basic elements without sacrificing any of the
properties of the whole
■ Structuralism was the approach and introspection was the methodology
○ Structuralism entails looking for patterns in thought
➢ William James and functionalism
○ William James (1842–1910), an American psychologist, opposed the structuralist approach ■
Examined how the structures identified by Wundt function in our lives
■ Structures of consciousness must have a function such as smelling and thinking
○ Argued that what is important is the function of the mind, such as how to solve a complex problem ○
James, influenced by Darwin, believed that the important thing to understand is how the mind fulfills
its purpose
○ This function-oriented approach is appropriately called functionalism
➢ Mary Whiton Calkins, Dorothea Dix, G. Stanley Hall, Margaret Floy Washburn
○ Mary Whiton Calkins: first female graduate student in psychology, but she was denied a PhD
because of her gender; she outscored all of the male students in her qualifying exams
○ Dorothea Dix: reformed mental institutions in the U.S.
○ G. Stanley Hall: first president the American Psychological Association, formed in 1892 ○
Margaret Floy Washburn: first female PhD in psychology and served as the second female
president of the American Psychological Association
Approaches
➢ Behavioral genetics
○ Behavioral genetics is the field of psychology that explores how particular behaviors may be
attributed to genetics
, ○ This perspective takes into account biological predispositions as well as the extent of influence
that the environment had
○ A person studying behavioral genetics might investigate to what extent risk-taking behavior in
adolescents is attributable to genetics
➢ Behaviorism
○ Behaviorism posits that psychology is the study of observable behavior and that the mind or
mental events are unimportant as they cannot be observed
○ Classical conditioning, first identified by Ivan Pavlov (1849–1936), was one of the behaviorists’
most important early findings; it is defined as a form of learning in which learning in which a
behavior comes to be elicited by a formerly neutral stimulus
■ John Watson (1878–1958) and his assistant Rosalie Rayner applied classical conditioning
to humans in the famed Little Albert experiment: they made loud sounds behind a
9-month-old whenever he would touch something white and furry, and he was afraid of
everything white and furry afterwards
○ B. F. Skinner (1904–1990), through the development of Skinner Box, described operant
conditioning, in which a subject learns to associate a behavior with an environmental outcome ■ A
Skinner box is a device used to record an animal's behavior in a compressed time frame in which it will
be rewarded or punished for engaging in certain behaviors
○ Behaviorism no longer prevailing approach in psychology but behavioral principles still used in
behavior modification: techniques in which psychological problems are considered to be the
product of learned habits and can be unlearned by using behavioral methods
➢ Biological
○ View genes, chemicals and body types as the determinant of personality
○ Genetics play a role in temperament: emotional style and characteristics that define how a person
deals with the world
➢ Biopsychosocial
○ Emphasizes the need to investigate the interaction of biological, psychological, and social factors
as contributing to a behavior or a mental process
➢ Cognitive/cognitive-behavioral
○ Cognitive psychology is an approach rooted in the idea that to understand people’s behavior, we
must first understand how they think
○ Cognitive psychology concerns itself with thinking, memory, and internal thought processes ○ This
approach combines the structuralist approach of looking at the subcomponents of thought and
functionalist approach of understanding the purpose of thought
○ Replaced the purely behavioral approach as the predominant psychological method used in U.S.
➢ Evolutionary
○ The study of behaviors and mental processes that are inherited from ancestors and how the
principles natural selection and genes present
, ○ Draws from Darwinian theories of natural selection and evolution
○ For example, fear is an adaptive evolutionary response and without fear our survival would be
jeopardized
➢ Gestalt
○ School of thought that looks at the human mind and behavior as a whole
○ Core belief is holism, or that the whole is greater than the sum of its parts
○ When trying to make sense of the world around us, we do not simply focus on every small
component; instead, our minds tend to perceive objects as part of a greater whole and as elements
of more complex systems
➢ Humanistic
○ Humanistic approach is rooted in the philosophical tradition of studying the roles of
consciousness, free will, and awareness of the human condition
○ Humanistic psychologists emphasize personal values and goals and how they influence behavior ○
Abraham Maslow (1908–1970) proposed the idea of self-actualization: we have a hierarchy of needs;
you can’t achieve the top level, self actualization, unless the previous levels have been achieved
because lower needs dominate an individual’s motivation as long as they are unsatisfied; from bottom
to top the levels are physiological needs, safety, belonging, self-esteem, self-actualization
○ Carl Rogers (1902–1987) believed in unconditional positive regard: people will naturally strive for
self actualization and high self-esteem, unless society taints them
➢ Psychodynamic/psychoanalytic
○ Developed by Freud (1856–1939) who believed that the id, superego and ego, fought for
dominance in an individual’s unconscious and thus compose their personality
■ Id (instincts): the primitive and instinctual part of the mind that contains sexual and
aggressive drives and hidden memories; exists in the unconscious mind
■ Ego (reality): reality principle/negotiator between desires of the id and limitations of the
environment; mediate between id and superego; exists in party conscious and partly
unconscious
■ Superego (morality): control the id's impulses, especially those which society forbids,
such as sex and aggression and persuades the ego to turn to moralistic goals rather than
realistic ones and to strive for perfection; operates on conscious and unconscious level
○ Believed innate drives for sex and aggression are the primary motives for our behavior and
personalities
➢ Sociocultural
○ Belief that the environment a person lives in has a great deal to do with how the person behaves
and how others perceive that behavior
○ Cultural values vary from society to society and must be taken into account if one wishes to
understand, predict, or control behavior
,Domains
➢ Biological
○ A question that concerns the effect of drugs on behavior refers to the biological domain
➢ Clinical
○ A question that considers treatments for someone addicted to drugs deals with the clinical domain
➢ Cognitive
○ What thoughts might someone entertain to justify their drug use?
➢ Counseling
○ How might a school counselor talk to a student about drugs?
➢ Developmental
○ At what ages might someone be more susceptible to peer pressure?
➢ Educational
○ How effective are school-based programs?
➢ Experimental
○ Dealing with experiments
➢ Industrial-organizational
○ Dealing with workplaces
➢ Personality
○ Dealing with personality
, ➢ Positive
○ Focuses on positive aspects and strengths of human behavior
➢ Psychometric
○ Dealing with how to measure things in psychology
➢ Social
○ A question about relationships between drug users and their families refers to the social domain
Methods
➢ Causation vs. correlation
○ Correlation is a relationship between two variables; when one variable changes, the other variable
also changes
○ Causation is when there is a real-world explanation for why this is logically happening; it implies a
cause and effect
➢ Descriptive statistics
○ Correlation coefficient
■ The correlation coefficient is a numerical value that indicates the degree and direction of
the relationship between two variables
■ Correlation coefficients range from +1.00 to –1.00; the sign (+ or –) indicates the
direction of the correlation, and the number (0 to + or –1.00) indicates the strength of the
relationship
○ Frequency distribution (normal, bimodal, positive or negative skew)
■ In a perfectly normal distribution, the mean, median, and mode are identical
■ If two numbers both have the greatest frequency (mode), the distribution is bimodal ■
A positive skew means that most values are on the lower end, but there are some
exceptionally large values
■ A negative skew means the opposite: most values are on the higher end, but there are
some exceptionally small values
○ Measures of central tendency
■ The mean is the arithmetic average of a set of numbers
■ The mode is the most frequently occurring value in the data set
■ The median is the number that falls exactly in the middle of a distribution of numbers ■
These statistics can be represented by a normal curve
○ Variation (range, standard deviation)
, ■ The range is simply the largest number minus the smallest number
■ The standard deviation determines the height and width of the graph
● When the standard deviation is large, the curve is short and wide
● When the standard deviation is small, the curve is tall and narrow
● In a typical distribution of numbers, about 68 percent of all scores are within one
standard deviation above or below the mean, and about 95 percent of all scores
are within two standard deviations above or below the mean
○ So, for example, IQ is typically said to have a mean of 100 and a
standard deviation of 15, so a person with a score of 115 is one
standard deviation above the mean
● Math questions about normal distributions can appear on the test, but because
skewed distributions do not all share the same mathematical properties,
questions about percentages and these distributions are often trick questions
● In skewed distributions, the median is a better indicator of central tendency than
the mean
➢ Groups
○ Control vs. experimental
■ The group receiving or reacting to the independent variable is the experimental group; the
control group does not receive the independent variable but should be kept identical in all
other respects
, ■ Using two groups allows for a comparison to be made and causation to be determined ○
Random assignment
■ Subjects are randomly assigned into both the experimental and control groups
■ Random assignment is done to ensure that each group has minimal differences
○ Random selection
■ Random sampling/selection is a way of ensuring maximum representativeness: the degree
to which a sample reflects the diverse characteristics of the population that is being
studied
● Unintentional sampling bias occurred during the 1948 U.S. Presidential
Election: a survey was conducted by randomly calling households and asking
them whom they intended to vote for, Harry Truman or Thomas Dewey, and
based on this phone survey, Dewey was projected to win but the results of the
election proved otherwise, as Truman was re-elected
● In 1948, having a telephone was not such a common thing, and households that
had them were generally wealthier; as a result, the “random” selection of
telephone numbers was not a representative sample because many people did not
have telephone numbers
■ Types of sampling bias
● The bias of selection from a specific real area occurs when people are selected in a
physical space; for example, if you wanted to survey college students on
whether or not they like their football team, you could stand on the quad and
survey the first 100 people that walk by; however, this is not completely random
because people who don’t have class at that time are unlikely to be represented
● Self-selection bias occurs when the people being studied have some control over
whether or not to participate; for example, an Internet survey might elicit
responses only from people who are highly opinionated and motivated to
complete the survey
● Pre-screening or advertising bias occurs often in medical research; how
volunteers are screened or where advertising is placed might skew the sample;
for example, if a researcher wanted to prove that a certain treatment helps people
to stop smoking, the mere act of advertising for people who “want to quit
smoking” might provide only a sample of people who are already highly
motivated to quit and might have done so without the treatment
● Healthy user bias occurs when the study population tends to be in better shape
than the general population
➢ Inferential statistics
○ Purpose is to determine whether or not findings can be applied to the larger population from which
, the sample was selected
○ The extent to which the sample differs from the population is known as sampling error ○
Psychologists typically want to be able to generalize the results of the experiment to a larger group of
people so it is important that the sample reflects the characteristics of the population as a whole and if
it does, then the sample is referred to as being representative
➢ Inter-rater reliability
○ It is also important that the study have reliability, which is whether or not the same results appear if
the experiment is repeated under similar conditions
○ A related concept is inter-rater reliability, the degree to which different raters agree on their
observations of the same data
➢ Operational definitions
○ The conceptual definition is the theory or issue being studied, the operational definition refers to
the way in which that theory or issue will be directly observed or measured in the study ○ In a study
on the effects of adolescent substance abuse, the way in which taking drugs affects adolescent
behavior is the conceptual definition, while the number of recorded days the student is absent from
school due to excessive use of substances is the operational definition
○ Operational definitions have to be internally and externally valid
➢ Study types
○ Case study
■ Case studies are intensive psychological studies of a single individual
■ These studies are conducted under the assumption that an in-depth understanding of
single cases will allow for general conclusions about other similar cases
■ Multiple case studies on similar cases are combined to draw inferences about issues ■
The danger of generalizing from the outcomes of case studies is that the individuals
studied may be atypical of the larger population, so researchers try to ensure that their
studies are generalizable—that is, applicable to similar circumstances because of the
predictable outcomes of repeated tests
■ Disadvantage because cannot assume cause & effect
○ Correlational
■ Involves assessing the degree of association between two or more variables that occurs
naturally; if the characteristics under consideration are related, they are correlated ■
Researchers do not directly manipulate variables but rather observe naturally occurring
differences
■ It is important to note that correlation does not prove causation; correlation simply shows
the strength of the relationship among variables
● For example, poor school performance may be correlated with lack of sleep;
however, we do not know if lack of sleep caused the poor performance, or if the
poor school performance caused the lack of sleep, or if some other unidentified
, factor influenced them both
■ One way to gather information for correlational studies is through surveys. Using either
questionnaires or interviews, one can accumulate a tremendous amount of data and study
relationships among variables.
● For example, survey studies might examine the relationship between
socioeconomic status and educational levels.
■ Correlational studies can be preferred to experiments because they are cheaper, consume
less time, easier to conduct, and some concepts can't be ethically studied in experiments ●
For example, you may want to study how child abuse affects self-efficacy in adulthood, but
no one will allow you to randomly assign half of your baby
participants to the child abuse condition
■ It can identify relationship between two variables but not cause & effect
○ Cross-sectional
■ Cross-sectional studies are designed to test a wide array of subjects from different
backgrounds to increase generalizability
■ It does not involve manipulating variables and happens at a single point in time ■ Allows
researchers to look at numerous characteristics at once (age, income, gender, etc.) ■ Done
because don’t have to wait a long time with the same subjects and can simply use people
from other gaps; the generational gap may cause differences however
○ Experimental
■ An experiment is an investigation seeking to understand relations of cause and effect ●
The experimenter changes a variable (cause) and measures how it changes
another variable (effect)
○ The manipulated variable is called the independent variable and the
dependent variable is what is measured
● At the same time, the investigator tries to hold all other variables constant so she
can attribute any changes to the manipulation
■ Subjects are randomly assigned into both the experimental and control group to ensure
that each group has minimal differences using single or double-blind method
● Single-blind design means that the subjects do not know whether they are in the
control or experimental group and in a double-blind design, neither the subjects
nor the researcher knows who is in the two groups
○ Double-blind studies are designed so that the experimenter does not
inadvertently change the responses of the subject, such as by using a
different tone of voice with members of the control group than the
experimental group
■ In some double-blind, the control group is given a placebo
which makes the control group to believe they’re the
