What is Psychology?
Psychology as a Natural Science and a Social Science
Psychology is the study of mental processes, behavior, and the relationship between
Mental processes include skills like learning, reasoning, emotion, and motivation.
To study psychology is to learn how humans and other organisms think,
understand, learn, perceive, feel, act, and interact with others.
Because psychology encompasses human and social issues as well as biological
and physiological ones, it is categorized as both a natural and social science.
As a natural science, psychology is concerned with the laws of nature.
As a social science, psychology involves the study of the laws of thoughts,
feelings, and behaviors of humans and other organisms.
The focus of psychology is generally on the individual, whether alone or in
interaction with others and the environment.
Psychologists profit from insights into human behavior offered by other
disciplines. Important examples are biology and computer science.
Psychology shares a focus on human behavior with other social-scientific
disciplines, such as sociology and anthropology.
Sociologists generally investigate larger aggregates of individuals, such as
occupational, societal, economic, or ethnic groups.
Cultural anthropologists seek to gain insight into various cultures.
Physical anthropologists study human evolution from simpler organisms.
Key Themes in the Evolution of Psychological Ideas
Georg Hegel, a German philosopher, referred to evolution of thought as dialectic,
a continuing intellectual dialogue in which thinkers strive for increased
First, thinkers strive to reach the truth by positioning an initial thesis, a statement
Other thinkers soon propose an antithesis, an opinion that takes a somewhat
different perspective and often contradicts the original thesis.
Eventually, other thinkers suggest a synthesis, the selective combining of the two
An example of the dialectic process in psychology is the attitude of researchers of
intelligence about the roles of nature (biology) and nurture (environment) in
Early in the 20th century researchers very much emphasized the role of
biological factors (thesis).
By the 1960s and the 1970s, there was a heavy emphasis on environment
as opposed to biology (antithesis).
But by the end of the century, most researchers realized that both nature
and nurture matter a great deal (synthesis).
Dialectical progression depends on permitting current theses to be challenged by
alternative, contrasting, and sometimes even radically divergent antitheses.
These challenges then may lead to syntheses of features of several old ideas.
Note that even when we reject outdated ideas, they still move us forward. They
serve a valuable springboard for new ways of looking at things. They are theses to
our innovative antitheses.
The Early History of Psychology
600 – 300 B.C.: Ancient Greece and Rome
Roots of Psychology in Philosophy and Physiology
• Psychology is rooted in two different approaches to human behavior.
1. The first is philosophy, a means of exploring and understanding the
general nature of many aspects of the world.
o Philosophy is pursued primarily through introspection, the self-
examination of inner ideas and experiences.
2. The second approach is physiology, the scientific study of living
organisms and of life-sustaining functions and processes, primarily
Hippocrates, Plato, and Aristotle: Thought, Observation, and Experimentation
• The Greek physician (and philosopher) Hippocrates, commonly known as the
father of medicine, left his mark on both physiology and philosophy.
• What sharply distinguished Hippocrates from archaic Greek philosophers and
physicians was his unorthodox idea that disease is not a punishment sent by the
• He also anticipated modern psychology by speculating that biological
malfunctions rather than demons cause mental illness.
• He thereby turned away from divine intervention as a cause of human behavior.
• Hippocrates also used unorthodox methods—empirical observation—to study
• He was particularly interested in discovering the source of the mind. He saw the
mind as a separate, distinct entity that controlled the body.
• The philosophical belief that the mind is qualitatively different from the body is
termed mind-body dualism.
• According to this view, the body is composed of physical substances, whereas the
mind is ethereal. Hippocrates proposed that the mind resides in the brain.
Two younger contemporaries of Hippocrates also considered the location of the
mind to be within the body.
1) Plato agreed that the mind resides within the brain.
2) His student Aristotle located the mind within the heart.
Plato and Aristotle differed in their views of mind and body because of their
differing views about the nature of reality.
According to Plato, reality resides not in the concrete objects we recognize
but in the ideal, abstract forms that these objects represent.
Aristotle, in contrast, believed that reality lies only in the concrete world
o Today we would call Aristotle an empiricist, a person who believes that we
acquire knowledge through empirical methods, obtaining evidence through
experience, observation, and experimentation.
o The Aristotelian view is associated with the empirical methods by which we
conduct research—in laboratories or in the field—on how people think and
o For Plato, however, empirical methods have little merit because true reality lies in
the abstract forms, not in the imperfect copies of reality that we see in the world
outside our minds.
o Observations of these imperfect, unreal objects and actions would be irrelevant to
the pursuit of the truth.
o Instead, Plato suggested a rationalist approach that asserts that knowledge is
most effectively acquired through logical methods, using philosophical analysis to
understand the world and people’s relationship to it.
1300-1600: The Renaissance and the Birth of Modern Science
o Science as we know it was born during the Renaissance, when direct observation
was established as the basis of knowledge.
o Many contemporary scientists seek to synthesize theory and observation.
o Theory should guide and give meaning to our observations, yet our theories
should be formed, modified, and perhaps even discarded as a result of our
o The development of psychology as a science today depends on a continual
interaction between theory and data.
o During the beginning of the modern period, however, many thinkers, such as
Descartes and Locke, emphasized either theory or data rather than their
1600-1850: The Early Modern Period
o The French philosopher Rene Descartes continued the dialectic of theory versus
data in the 17th century.
o Descartes agreed with Plato’s rationalist belief that the introspective, reflective
method is superior to empirical methods for finding the truth.
o Also like Plato, Descartes espoused the ideas of mind-body dualism, believing
that the mind and the body are separate and qualitatively different, and of innate
(versus acquired) knowledge.
o In contrast, the British empiricist philosopher John Locke believed that humans
are born without knowledge, and they must therefore seek knowledge through
o Locke’s term for this human condition is tabula rasa, which means “blank slate”
in Latin. Experience “writes” knowledge upon us.
o In the 18th century, the debates about dualism versus monism (the belief that mind
and body are one) and empiricism versus rationalism reached a peak.
o German philosopher Immanuel Kant began the process of dialectic synthesis for
o Kant believed that the quest for understanding mental processes requires both
rationalism and empiricism working together.
Early Psychological Approaches to Behavior
When psychology was starting out as a field in the late 1800s, it was viewed by some as a
branch of philosophy and by others as a branch of medicine.
Gradually, the psychological branches of philosophy and medicine diverged from the two
Psychology was increasingly seen as a distinct, unified, scientific discipline that focuses
on the study of mind and behavior.
Structuralism: Taking Inventory of the Mind
o In structuralism, the first major school of thought in psychology, the goal was to
understand the mind by analyzing its elements, such as particular sensations or
o Although structuralism is no longer a dynamic force, it is important for having
taken the first steps toward making psychology a systematic, empirical science.
o A forerunner to structuralism was the perspective of German psychologist
Wilhelm Wundt, who some considered the “founder” of modern psychology.
o Wundt believed that psychology should focus on immediate and direct (for ex.,
seeing narrow, vertical, spiky, green protrusions of varying lengths and widths,
amassed closely together on a 2D surface), as opposed to mediated or interpreted,
conscious experience (the inferred concepts of lawn and grass).
o For Wundt, the optimal method by which a person could be trained to analyze
such sensory experiences was a form of self-observation called introspection.
o This method involves looking inward at pieces of information passing through
consciousness—a form of self-observation.
o Wundt’s student Edward Titchener, like Wundt believed that all consciousness
could be reduced to elementary states.
o After using strict structuralist principles in his teaching, research, and writing,
Titchener changed his mind toward the end of his life.
Like others, he recognized the problem that structuralism proposed too
many elementary sensations. The number of such sensations could
increase without end.
Structuralism also provided no means for understanding processes of
Furthermore, it was probably too rigidly tied to a single methodology:
Functionalism: Why Do We Do What We Do
The roots of structuralism are in Germany, but its countermovement,
functionalism, originated in the United States—the first U.S.-born movement in
Functionalism focuses on active psychological processes rather than on passive
psychological structures or elements.
The key difference between structuralists and functionalists was in the
fundamentally different questions that they asked.
Whereas structuralists asked, What are the elementary contents, the structures, of
the human mind?, functionalists asked, What do people do, and why do they do
Another way of viewing the difference between structuralism and functionalism is
that structuralists considered humans and other organisms as largely passive in
analyzing incoming sensations.
Functionalists, in contrast, viewed humans and others as more actively engaged in
processing their sensations and formulating their actions.
Functionalists’ openness to diverse methodologies broadened the scope of
psychological methods. Among the various approaches used by the functionalists
was experimentation on animals.
A leader in the functionalist movement was William James, whose chief
contribution to the field of psychology was a single book, his landmark Principles
James is particularly well known for his pragmatic theorizing about
consciousness. He was a leader in guiding functionalism toward pragmatism, a
view of science and psychology that asserts that knowledge is validated by its
Functionalism, like structuralism, did not survive as an organized school of
thought. The term function lacked clear definition as applied to psychology. the
result was that the school did not hold together.
Associationism: Early Ideas About Learning
o Associationism, like functionalism, was a less rigid school of psychology than
an influential way of thinking.
o In general, associationists are mainly interested in the middle- to higher-level
mental processes, such as those of learning (this is opposite of Wundt’s
insistence on studying elementary sensations).
o Associationism examines how events or ideas can become associated in the
mind, thereby resulting in a form of learning.
o An influential associationist, the German experimenter Herman Ebbinghaus
was the first experimenter to apply associationist principles systematically.
o He used self-observation to study and quantify the relationship between
rehearsal—conscious repetition—and recollection of material.
o He found that frequent repetition mixes mental associations more firmly in
memory, by extension, that repetition aids in learning.
o Ebbinghaus’s ideas were elaborated by Edwin Guthrie, who proposed that two
observed events (a stimulus and a response) become associated through their
close temporal contiguity—their occurring very close together in time.
o In contrast, Edward Lee Thorndike, held that “satisfaction”, rather than
Guthrie’s temporal contiguity, is the key to forming assosciations.
o Thorndike called this principle the law of effect: Over time the actions (“the
effect”) for which an organism is rewarded (“the satisfaction”) are
strengthened and are therefore are more likely to occur again in the future.
o Associationism in its strictest form has not survived. The school of thought
was overly simplistic and did not explain cognition, emotion, or many other
o Nevertheless, associationism made a contribution to contemporary thinking in
psychology and has been linked to many other theoretical viewpoints.
Psychology in the 20th Century
An important 20th century contribution was the idea that the primary subject matter of
psychology ought to be the self.
In her self-psychology, Mary Whiton Calkins, argued both that the self should be the
focus of psychological investigation and that the self must be studied in its social context.
From Associationism to Behaviorism
Ivan Pavlov and Classically Conditioned Learning
• In Russia, Nobel Prize-winning physiologist Ivan Pavlov studied involuntary
• He began with the observation that dogs salivated in response to the sight of lab
technician who fed them before the dogs even saw whether the technician had
• To Pavlov, this response indicated classical conditioned learning, whereby an
originally neutral stimulus comes to be associated with a stimulus that already
produces a particular physiological or emotional response.
• Pavlov believed that the dogs have no conscious control over this form of
Behaviorism: A Search for Rigor and Reduction
Behaviorism is a theoretical outlook that emphasizes the idea that psychology should be
John Watson and Radical Behaviorism
• The individual usually acknowledged as the founder of radical behaviorism is
American psychologist John Watson.
• John Watson had no use for internal mental contents or mechanisms. His radical
conception of behaviorism stated that any behavior can be shaped or controlled.
• This view is dramatized in his famous challenge: “Give me a dozen infants….and
I’ll guarantee to take any one at random and train him to become any type of
specialist I might select—doctor, lawyer, artist, merchant-chief and yes, even
beggar and thief—regardless of his talents…”
• Behaviorism differed from earlier movements in psychology in its emphasis on
nonhuman animal rather than human research participants.
• Watson himself preferred animal subjects. From his point of view, the simpler the
organism’s emotional and physiological makeup, the less the researcher needs to
worry about any of the interference that can plague psychological research with
humans as participants.
• An American behavioral psychologist who tried to connect the involuntary
learning studied by Pavlov with the voluntary learning studied by Watson and
Thorndike was Clark Hull.
• Hull’s work was ignored for a decade before its importance was recognized.
• Hull was particularly influential for his belief that the laws of behavior could be
quantified—expressed in terms of numerical quantities—like the laws of other
Skinner’s Experimental Analysis of Behavior
• In modern times, radical behaviorism has seemed almost synonymous with the
work of one of its most radical proponents, B.F. Skinner.
• Skinner, unlike Watson, was not a S-R (stimulus-response) psychologist.
• Skinner distinguished between two different kinds of learned behavior.
Respondent behavior, the kind studied by Pavlov, is involuntary. It is
elicited by a definite stimulus (such as food or even the sight of the lab
Operant behavior, on the other hand, is largely voluntary. It cannot be
simply or certainly elicited.
• The probability of an operant behavior can be increased, however, if it is followed
by an event referred to as a reinforcer.
• The radical behaviorist approach, by ignoring internal states, effectively limits
itself. It has difficulty explaining many aspects of behavior, such as acquisition
and use of language.
• Despite many criticisms, behaviorism has had a great impact on the development
of psychology as a rigorous science grounded in empirical evidence.
Gestalt Psychology: the Whole is Different than the Sum of Its Parts
Of the many critics of behaviorism, Gestalt psychologists have been the most
Actually, the movement was not only a reaction against the early behaviorist
tendency to break down behaviors into stimulus-response units.
It was also a reaction against the structuralist tendency to analyze mental
processes by studying elementary sensations.
According to Gestalt psychology, psychological phenomena are best understood
when viewed as organized, structured wholes—that is, holistically—not when
they are analyzed into myriad component elements.
The Gestalt movement originated in Germany, but then spread to the United
States and other countries.
Gestalt psychology is usually traced back to the work of German psychologist
He collaborated with Kurt Koffka and Wolfgang Kohler to form the new school
The maxim “The whole is different from the sum of its parts” aptly sums up the
The Gestaltist applied this framework to many areas in psychology, such as
The Gestalt perspective has been criticized on several grounds.
1. It generated little data relative to the abundance of theory it provided.
2. Studies conducted under the Gestalt approach tended to lack careful