'Psychology' (from Greek: ψυχή, ''psukhē'', "spirit, soul"; λόγος, ''logos'', "knowledge") is both an
academic and
applied discipline involving the
scientific study of
mental processes and
behavior. Psychologists study such phenomena as
perception,
cognition,
emotion,
personality,
behavior, and
interpersonal relationships. Psychology also refers to the application of such
knowledge to various spheres of
human activity, including issues related to
daily life—e.g.
family,
education, and
work—and the
treatment of
mental health problems.
Psychology is one of the
behavioral sciences—a broad field that spans the
social and
natural sciences. Psychology attempts to understand the role human behavior plays in social dynamics while incorporating
physiological and
neurological processes into its conceptions of mental functioning. Psychology includes many sub-fields of study and application concerned with such areas as
human development,
sports,
health,
industry,
law, and
spirituality.
History
Main articles: History of psychology
Early development
Rudolf Goclenius
, as well as
psychophysics, began with the development of the
experimental
scientific method by
Ibn al-Haytham (Alhacen) in the 1010s. In his ''
Book of Optics'', he made use of the experimental method in his pioneering work on the psychology of
visual perception.
[1]
The first use of the term "psychology" is attributed to the
German scholastic philosopher Rudolf Goeckel (Latinized
Rudolph Goclenius), published in
1590.
[2] More than six decades earlier, the Croatian humanist
Marko Marulić used the term in the title of a work which was subsequently lost.
[3]
The term did not fall into popular usage until the German idealist philosopher,
Christian Wolff (1679-1754) used it in his ''Psychologia empirica and Psychologia rationalis'' (1732-1734). This distinction between empirical and rational psychology was picked up in
Diderot's ''Encyclopedie'' and was popularized in France by
Maine de Biran.
The root ''
psyche'' is very roughly equivalent to "
soul" in Greek, and ''
ology'' equivalent to "
study". Psychology came to be considered a study of the soul (in a religious sense of this term) much later, in Christian times. Psychology as a medical discipline can be seen in
Thomas Willis' reference to psychology (the "Doctrine of the Soul") in terms of
brain function, as part of his
1672 anatomical treatise "De Anima Brutorum" ("Two Discourses on the Souls of Brutes"). Until about the end of the
19th century, psychology was regarded as a branch of
philosophy.
Beginning of the scientific era
In
1879,
Wilhelm Wundt (1832-1920), known as "the father of psychology", founded a laboratory for the study of psychology at
Leipzig University in
Germany.
[4] The American philosopher
William James published his seminal book, ''
Principles of Psychology''
[5], in 1890, laying the foundations for many of the questions that
psychologists would focus on for years to come. Other important early contributors to the field include
Hermann Ebbinghaus (1850–1909), a pioneer in the experimental study of
memory at the
University of Berlin; and the
Russian
physiologist Ivan Pavlov (1849-1936), who investigated the
learning process now referred to as
classical conditioning.
Meanwhile, during the 1890s, the
Austrian physician
Sigmund Freud, who was trained as a
neurologist and had no formal training in experimental psychology, had developed a method of
psychotherapy known as
psychoanalysis. Freud's understanding of the mind was largely based on interpretive methods and
introspection, and was focused in particular on resolving mental distress and
psychopathology. Freud's theories became very well-known, largely because they tackled subjects such as
sexuality and
repression as general aspects of psychological development. These were largely considered
taboo subjects at the time, and Freud provided a catalyst for them to be openly discussed in polite society. Although Freud's theories are of limited (mostly historical) interest to modern academic psychology departments, his application of psychology to clinical work has been very influential. Followers of Freud who accept the basic ideas of psychoanalysis but alter it in some way are called
neo-Freudians.
Rise and fall of behaviorism
Partly in reaction to the subjective and introspective nature of Freudian psychology, and its focus on the recollection of childhood experiences, during the early decades of the
20th century,
behaviorism gained popularity as a guiding psychological theory. Founded by
John B. Watson and embraced and extended by
Edward Thorndike, Hull, Clark,
Tolman, and later
B.F. Skinner), behaviorism was grounded in studies of animal behavior. Behaviorists shared the view that the subject matter of psychology should be operationalized with standardized procedures which led psychology to focus on ''behavior'', 'not' the mind or consciousness.
[6] They doubted the validity of introspection for studying internal mental states such as
feelings,
sensations,
beliefs,
desires, and other unobservables.
In "Psychology as the Behaviorist Views It" (1913),
[7] Watson argued that psychology "is a purely objective experimental branch of natural science," that "introspection forms no essential part of its methods", and that "the behaviorist recognizes no dividing line between man and brute." Skinner rejected hypothesis testing as a productive method of research, considering it to be too conducive to speculative theories that would promote useless research and stifle good research.
[8]
Behaviorism reigned as the dominant model in psychology throughout the first half of the 20th century, largely due to the creation of
conditioning theories as scientific models of human behavior, and their successful application in the workplace and in fields such as
advertising and
military science.
However, it became increasingly clear that, although it had made some important discoveries, behaviorism was deficient as a guiding theory of human behavior.
[Miller, G.A. (2003). The cognitive revolution: a historical perspective. ''Trends in Cognitive Sciences.'' 7:141-144. (online)] Noam Chomsky's review of Skinner's book ''
Verbal Behavior'' (which aimed to explain
language acquisition in a behaviorist framework) is considered one of the major factors in the ending of behaviorism's reign.
In his theory of
Generative Grammar Chomsky demonstrated that language could not be learned purely from conditioning, because people could produce sentences unique in structure and meaning that couldn't possibly be generated solely through experience of natural language — implying that there must be internal states of mind that behaviorism rejected as illusory.
[9] Similarly, work by
Albert Bandura showed that children could
learn by social observation, without any change in overt behavior, and so must be accounted for by internal representations
[10] Humanism focuses on uniquely human issues and fundamental issues of life, such as self-identity, death, aloneness, freedom, and meaning. Some of the founding theorists behind this school of thought were
Abraham Maslow who formulated a
hierarchy of human needs,
Carl Rogers who created and developed
Client-centered therapy, and
Fritz Perls who helped create and develop
Gestalt therapy. It has become so influential as to be called the "third force" within psychology (preceded by behaviorism and psychoanalysis).
[11]
Cognitivism takes the stage
The rise of computer technology also promoted the metaphor of mental function as
information processing. This, combined with a scientific approach to studying the mind, as well as a belief in internal mental states, led to the rise of
cognitivism as a popular model of the mind.
Links between
brain and
nervous system function were also becoming common, partly due to the experimental work of people such as
Charles Sherrington and
Donald Hebb, and partly due to studies of people with
brain injury (see
cognitive neuropsychology). With the development of technologies for accurately measuring brain function,
neuropsychology and
cognitive neuroscience have become some of the most active areas in contemporary psychology. With the increasing involvement of other disciplines (such as
philosophy,
computer science and
neuroscience) in the quest to understand the mind, the umbrella discipline of
cognitive science has been created as a means of focusing such efforts in a constructive way.
Principles
Mind and brain
Psychology describes and attempts to explain consciousness, behavior, and social interaction. Empirical psychology is primarily devoted to describing human experience and behavior as it actually occurs. Since the 1980s, psychology has begun to examine the relationship between consciousness and the
brain or
nervous system. It is still not clear how these interact: does consciousness determine brain states or do brain states determine consciousness - or are both going on in various ways? Or, is
consciousness some sort of complicated 'illusion' that bears no direct relationship to neural processes? Perhaps to understand this, it is necessary to define "
consciousness" and "brain state". An understanding of brain function is increasingly being included in psychological theory and practice, particularly in areas such as
artificial intelligence,
neuropsychology, and
cognitive neuroscience.
Schools of thought
Main articles: List of psychological schools
Various schools of thought have argued for a particular model to be used as a guiding theory by which all, or the majority, of human behavior can be explained. The popularity of these has waxed and waned over time. Some
psychologists may think of themselves as adherents to a particular school of thought and reject the others, although most consider each as an approach to understanding the mind, and not necessarily as mutually exclusive theories.
Ideas of uniting psychology
Journal of Clinical Psychology devoted two issues to discuss on unified theory of psychology
[12][13]. Rand and Ilardi
[14] notice that from its inception as a distinct discipline psychology has been characterized by conceptual disarray and integration across research enclaves and theoretical factions is limited. Rand and Ilardi differentiate some dimensions where different representatives of psychology might be.
★
dualism or
materialism: mind and body can be seen different (dual) entities or with one intertwined (material) entity
★
science and
practice: applied psychologists are still able to maintain relative independence from the science of psychology
★
science and
humanism: there can be disagreement on such fundamental philosophical issues as
determinism versus indeterminism,
objectivism versus
intuition,
data versus
theory, and
nomothetic versus
idiographic modes of investigation
★
behaviorism and
mentalism: conflict between so-called mentalists and behaviorists is one of the deepest rifts in psychology
There have been several proposals for
meta-theory such as
Tree of Knowledge System. Rand and Ilardi notice that advancement of technology may drive towards unified theory in psychology, for example
neuroimaging techniques have revealed previously unknown phenomenon.
Subfields
Psychology encompasses a vast domain, and includes many different approaches to the study of mental processes and behavior. Below are the major areas of inquiry that comprise psychology, divided into fields of research psychology and fields of applied psychology. A comprehensive list of the sub-fields and areas within psychology can be found at the
list of psychological topics and
list of psychology disciplines.
Fields of research
Main articles: Qualitative psychological research,
Quantitative psychological research
Research psychology encompasses the study of behavior for use in
academic settings, and contains numerous areas. It contains the areas of
abnormal psychology,
biological psychology,
cognitive psychology,
comparative psychology,
developmental psychology,
personality psychology,
social psychology and others. Research psychology is contrasted with
applied psychology.
Abnormal psychology
Main articles: Abnormal psychology
Abnormal psychology is the study of
abnormal behavior in order to describe, predict, explain, and change abnormal patterns of functioning. Abnormal psychology studies the nature of
psychopathology and its causes, and this knowledge is applied in
clinical psychology to treat patients with psychological disorders.
In the study of abnormal behavior, it can be difficult to define the line between which behaviors are considered normal and which are not. In general, abnormal behaviors must be maladaptive and cause an individual subjective discomfort (signs of emotional distress). Generally, abnormal behaviors are classified as:
★ Abnormal as in "infrequent" in relation to the overall population.
★ Abnormal as in "maladaptive". The behavior fails to promote well being, growth, and fulfillment of a person.
★ Abnormal as in "deviant". The behavior is not socially acceptable.
★ Abnormal as in "unjustifiable". The behavior that cannot be rationalized.
Biological psychology
Image of the human brain. The arrow indicates the position of the
hypothalamus.
,
Neuropsychology,
Physiological psychology,
Cognitive Neuroscience,
Evolutionary psychology
Biological psychology is the scientific study of the biological bases of behavior and mental states. Because all behavior is controlled by the
central nervous system, it is sensible to study how the
brain functions in order to understand behavior. This is the approach taken in
behavioral neuroscience,
cognitive neuroscience, and
neuropsychology. Neuropsychology is the branch of psychology that aims to understand how the structure and function of the
brain relate to specific behavioral and psychological processes. Often neuropsychologists are employed as scientists to advance scientific or medical knowledge. Neuropsychology is particularly concerned with the understanding of
brain injury in an attempt to work out normal psychological function.
The approach of
cognitive neuroscience to studying the link between brain and behavior is to use
neuroimaging tools, such as
fMRI, to observe which areas of the brain are active during a particular task.
Cognitive psychology
Neural network with two layers
The nature of
thought is another core interest in psychology.
Cognitive psychology studies
cognition, the
mental processes underlying behavior. It uses
information processing as a framework for understanding the mind.
Perception,
learning,
problem solving,
memory,
attention,
language and
emotion are all well researched areas. Cognitive psychology is associated with a school of thought known as
cognitivism, whose adherents argue for an
information processing model of mental function, informed by
positivism and
experimental psychology.
Cognitive science is very closely related to cognitive psychology, but differs in some of the research methods used, and has a slightly greater emphasis on explaining mental phenomena in terms of both behavior and neural processing.
Both areas can use
computational models to simulate phenomena of interest. Because mental events cannot directly be observed, computational models provide a tool for studying the functional organization of the mind. Such models give cognitive psychologists a way to study the "software" of mental processes independent of the "hardware" it runs on, be it the brain or a computer.
Comparative psychology
Main articles: Comparative psychology
Comparative psychology refers to the study of the behavior and mental life of
animals other than human beings. It is related to disciplines outside of psychology that study animal behavior, such as
ethology. Although the field of psychology is primarily concerned with humans, the behavior and mental processes of
animals is also an important part of psychological research, either as a subject in its own right (e.g.,
animal cognition and ethology), or with strong emphasis about evolutionary links, and somewhat more controversially, as a way of gaining an insight into human psychology by means of comparison or via animal models of emotional and behavior systems as seen in neuroscience of psychology (e.g.,
affective neuroscience and
social neuroscience).
Developmental psychology
How do infants experience the world?
Mainly focusing on the development of the human mind through the life span,
developmental psychology seeks to understand how people come to perceive, understand, and act within the world and how these processes change as they age. This may focus on intellectual, cognitive, neural, social, or
moral development. Researchers who study children use a number of unique research methods to make observations in natural settings or to engage them in experimental tasks. Such tasks often resemble specially designed games and activities that are both enjoyable for the child and scientifically useful, and researchers have even devised clever methods to study the mental processes of small infants. In addition to studying children, developmental psychologists also study
aging and processes throughout the life span, especially at other times of rapid change (such as adolescence and old age).
Urie Bronfenbrenner's theory of development in context (''The Ecology of Human Development'' - ISBN 0-674-22456-6) is influential in this field, as are those mentioned in "Educational psychology" immediately below, as well as many others. Developmental psychologists draw on the full range of theorists in scientific psychology to inform their research.
Personality psychology
Main articles: Personality psychology
Personality psychology studies enduring psychological patterns of
behavior,
thought and
emotion, commonly called an individual's . Theories of personality vary between different psychological schools.
Trait theories attempts to break personality down into a number of traits, by use of
factor analysis. The number of traits have varied between theories. One of the first, and smallest, models was that of
Hans Eysenck, which had three dimensions:
extroversion—
introversion,
neuroticism—
emotional stability, and
psychoticism.
Raymond Cattell proposed a theory of
16 personality factors. The theory that has most empirical evidence behind it today may be the "
Big Five" theory, proposed by
Lewis Goldberg, and others.
A different, but well known, approach to personality is that of
Sigmund Freud, whose ''structural theory of personality'' divided personality into the
ego, superego, and id. Freud's theory of personality has been criticized by many, including many mainstream psychologists.
Quantitative psychology
Quantitative psychology involves the application of
mathematical and
statistical modeling in psychological research, and the development of statistical methods for analyzing and explaining behavioral data. The term ''Quantitative psychology'' is relatively new and little used (only recently have Ph.D. programs in quantitative psychology been formed), and it is loosely covers the longer standing subfields
psychometrics and
mathematical psychology.
Psychometrics is the field of psychology concerned with the theory and technique of psychological
measurement, which includes the measurement of knowledge, abilities, attitudes, and personality traits. Measurement of these unobservable
phenomena is difficult, and much of the research and accumulated knowledge in this discipline has been developed in an attempt to properly define and quantify such phenomena. Psychometric research typically involves two major research tasks, namely: (i) the construction of
instruments and procedures for measurement; and (ii) the development and refinement of theoretical approaches to measurement.
Whereas psychometrics is mainly concerned with individual differences and population structure,
mathematical psychology is concerned with modeling of mental and motor processes of the average individual.
Psychometrics is more associated with
educational,
personality, and
clinical psychology. Mathematical psychology is more closely related to
psychonomics/
experimental and
cognitive, and
physiological psychology and (
cognitive)
neuroscience.
Social psychology
Main articles: Social psychology (psychology)
Social psychology is the study of the nature and causes of human social behavior, with an emphasis on how people think towards each other and how they relate to each other. Social Psychology aims to understand how we make sense of social situations. For example, this could involve the influence of others on an individual's behavior (e.g.,
conformity or
persuasion), the perception and understanding of social cues, or the formation of
attitudes or
stereotypes about other people.
Social cognition is a common approach and involves a mostly cognitive and scientific approach to understanding social behavior.
Fields of application
Main articles: Applied psychology
Applied psychology encompasses both psychological research that is designed to help individuals overcome practical problems and the application of this research in applied settings. Much of applied psychology research is utilized in other fields, such as
business management,
product design,
ergonomics,
nutrition,
law and
clinical medicine.
Applied psychology includes the areas of
clinical psychology,
industrial and organizational psychology,
human factors,
psychology and law,
health psychology,
school psychology,
community psychology and others.
Clinical psychology
Main articles: Clinical psychology
Clinical psychology includes the study and application of psychology for the purpose of understanding, preventing, and relieving psychologically-based distress or
dysfunction and to promote subjective
well-being and personal development.
[15] Central to its practice are
psychological assessment and
psychotherapy, although clinical psychologists may also engage in research, teaching, consultation, forensic testimony, and program development and administration.
[16]
Some clinical psychologists may focus on the clinical management of patients with
brain injury—this area is known as
clinical neuropsychology. In many countries clinical psychology is a regulated
mental health profession.
The work performed by clinical psychologists tends to be done inside various therapy models, all of which involve a formal relationship between professional and client—usually an individual, couple, family, or small group—that employs a set of procedures intended to form a therapeutic alliance, explore the nature of psychological problems, and encourage new ways of thinking, feeling, or behaving. The four major perspectives are
Psychodynamic,
Cognitive Behavioral,
Existential-Humanistic, and
Systems or Family therapy. There has been a growing movement to integrate these various therapeutic approaches, especially with an increased understanding of issues regarding culture, gender, spirituality, and sexual-orientation. With the advent of more robust research findings regarding psychotherapy, there is growing evidence that most of the major therapies are about of equal effectiveness, with the key common element being a strong therapeutic alliance.
[17][18] Because of this, more training programs and psychologists are now adopting an
eclectic therapeutic orientation.
Clinical psychologists do not usually
prescribe medication, although there is a growing movement for psychologists to have limited prescribing privileges.
[19] In general, however, when medication is warranted many psychologists will work in cooperation with psychiatrists so that clients get all their therapeutic needs met.
Clinical psychologists may also work as part of a team with other professionals, such as
social workers and
nutritionists.
Counseling psychology
Main articles: Counseling psychology
Counseling psychology is a psychology specialty that facilitates personal and
interpersonal functioning across the lifespan with a focus on emotional, social,
vocational, educational, health-related, developmental, and organizational concerns. Counselors are primarily clinicians, using psychotherapy and other interventions in order to treat clients. Traditionally, counseling psychology has focused more on normal developmental issues and everyday
stress rather than psychopathology, but this distinction has softened over time. Counseling psychologists are employed in a variety of settings, including universities, hospitals, schools, governmental organizations, businesses, private practice, hospitals, and community mental health centers.
Educational psychology
Main articles: Educational psychology
Educational psychology is the study of how humans learn in
educational settings, the effectiveness of educational interventions, the psychology of teaching, and the
social psychology of
schools as organizations. The work of child psychologists such as
Lev Vygotsky,
Jean Piaget and
Jerome Bruner has been influential in creating
teaching methods and educational practices.
Psychology and Law
Main articles: Legal psychology ,
Forensic psychology
Together,
Forensic psychology and
Legal Psychology compose the area known as Psychology and Law.
Most typically, 'forensic psychology' is practiced by
clinical psychologists, and involves a clinical analysis of a particular individual and an assessment of some specific psycho-legal question. Typical forensic psychology issues include child custody disputes, child abuse or neglect, assessing personal capacity to manage one's affairs, matters of competency to stand trial, criminal responsibility, personal injury, and advising judges in matters relating to sentencing regarding various mitigants and the actuarial assessment of future risk.
Criminal profiling is a branch of this field.
'Legal psychology' is a research-oriented field populated with researchers from several different areas within psychology (although
social and
cognitive psychologists are typical). Legal psychologists explore such topics as jury decision-making, eyewitness memory, scientific evidence, and legal policy. The term "legal psychology" has only recently come into use, and typically refers to any non-clinical law-related research.
Health psychology
Main articles: Health psychology
Health psychology is the application of psychological theory and research to health, illness and health care. Whereas clinical psychology focuses on mental health and neurological illness,
health psychology is concerned with the psychology of a much wider range of health-related behavior including healthy eating, the doctor-patient relationship, a patient's understanding of health information, and beliefs about illness. Health psychologists may be involved in public health campaigns, examining the impact of illness or health policy on
quality of life and in research into the psychological impact of health and social care.
Human factors psychology
Main articles: Human factors
Human factors psychology (sometimes called Engineering Psychology) is the study of how cognitive and psychological processes affect our interaction with tools and objects in the environment. The goal of research in human factors psychology is to better design objects by taking into account the limitations and biases of human mental processes and behavior.
Industrial and organizational psychology
Main articles: Industrial and organizational psychology
Industrial and organizational psychology (I/O) is among the newest fields in psychology.
Industrial Psychology focuses on improving, evaluating, and predicting job performance while
Organizational Psychology focuses on how organizations impact and interact with individuals. In 1910, through the works and experiments of
Hugo Munsterberg and
Walter Dill Scott,
Industrial Psychology became recognized as a legitimate part of the social science.
[20] Organizational Psychology was not officially added until the 1970s and since then, the field has flourished. The
Society for Industrial Organizational Psychology has approximately 3400 professional members and 1900 student members. These two numbers combine to make up only about four percent of the members in the
American Psychology Association but the number has been rising since 1939 when there were only one hundred professional I/O psychologists.
I/O psychologists are employed by academic institutions, consulting firms, internal human resources in industries, and governmental institutions. Various universities across the United States are beginning to strengthen their I/O Psychology programs due to the increase of interest and job demand in the field.
Industrial organizational psychologists look at questions regarding things such as who to hire, how to define and measure successful job performance, how to prepare people to be more successful in their jobs, how to create and change jobs so that they are safer and make people happier, and how to structure the organization to allow people to achieve their potential.
School psychology
Main articles: School psychology
School psychology is the area of discipline that is dedicated to helping young people succeed academically, socially, and emotionally. School psychologists collaborate with educators, parents, and other professionals to create safe, healthy, and supportive learning environments for all students that strengthen connections between home and school. They are trained to be experts in educational and behavioral assessment, intervention, prevention, and consultation, and many have extensive training in research.
[21] Currently, school psychology is the only field in which a professional can be called a "psychologist" without a doctoral degree, with the
National Association of School Psychologists (NASP) recognizing the
Specialist degree as the entry level. This is a matter of controversy as the
APA does not recognize anything below a doctorate as the entry level for a psychologist. Specialist-level school psychologists, who typically receive three years of graduate training, function almost exclusively within school systems, while those at the doctoral-level are found in a number of other settings as well, including universities, hospitals, clinics, and private practice.
Research methods
Wilhelm Maximilian Wundt (seated) was a German psychologist, generally acknowledged as a founder of
experimental psychology.
Research in psychology is conducted in broad accord with the standards of the
scientific method, encompassing both
qualitative ethological and
quantitative statistical modalities to generate and evaluate
explanatory hypotheses with regard to psychological
phenomena. Where research ethics and the state of development in a given research domain permits, investigation may be pursued by
experimental protocols. Psychology tends to be eclectic, drawing on scientific knowledge from other fields to help explain and understand psychological phenomena.
Qualitative psychological research utilizes a broad spectrum of observational methods, including
action research,
ethography,
exploratory statistics,
structured interviews, and
participant observation, to enable the gathering of rich information unattainable by classical experimentation. Research in
humanistic psychology is more typically pursued by
ethnographic,
historical, and
historiographic methods.
The
testing of different aspects of psychological function is a significant area of contemporary psychology.
Psychometric and
statistical methods predominate, including various well-known standardized tests as well as those created ad hoc as the situation or experiment requires.
Academic psychologists may focus purely on research and psychological theory, aiming to further psychological understanding in a particular area, while other psychologists may work in
applied psychology to deploy such knowledge for immediate and practical benefit. However, these approaches are not mutually exclusive and most psychologists will be involved in both researching and applying psychology at some point during their career. Clinical psychology, among many of the various disciplines of psychology, aims at developing in practicing psychologists knowledge of and experience with research and experimental methods which they will continue to build up as well as employ as they treat individuals with psychological issues or use psychology to help others.
When an area of interest requires specific training and specialist knowledge, especially in applied areas, psychological associations normally establish a governing body to manage training requirements. Similarly, requirements may be laid down for university degrees in psychology, so that students acquire an adequate knowledge in a number of areas. Additionally, areas of practical psychology, where psychologists offer treatment to others, may require that psychologists be licensed by government regulatory bodies as well.
Controlled experiments
Main articles: Experiment
Experimental psychological research is conducted in a laboratory under controlled conditions. This method of research relies on the application of the
scientific method to understand behavior. Experiments use several types of measurements, including rate of response,
reaction time, and various
psychometric measurements. Experiments are designed to test specific
hypotheses (deductive approach) or evaluate functional relationships (inductive approach). They are important for psychological research because they allow researchers to establish causal relationships between different aspects of behavior and the environment. Importantly, in an experiment, one or more variables of interest are controlled by the experimenter (independent variable) and another variable is measured in response to different conditions (dependent variable). (See also
hypothesis testing.) Experiments are one of the primary research methodologies in many areas of psychology, particularly
cognitive/
psychonomics,
mathematical psychology,
psychophysiology and
biological psychology/
cognitive neuroscience.
As an example, suppose an experimenter wanted to answer the following question: does talking on a phone affect one's ability to stop quickly while driving? To answer this, the experimenter would want to show that a subject's stopping time is different when they are talking on a phone versus when they are not. If the experiment is properly conducted in a controlled environment and a difference between the two conditions is found, the experimenter would be able to show a causal relationship between phone use and stopping time. In addition to potential practical benefits, this type of experiment may have important theoretical results, such as helping to explain the processes that underlie
attention in humans.
Experiments on humans have been put under some controls; namely informed and voluntary consent. After WWII, the
Nuremberg Code was established, because of Nazi abuses of experimental subjects. Later, most countries (and scientific journals) adopted the
Declaration of Helsinki. In the US, the
NIH established the
IRB in 1966. And in 1974, adopted the
National Research Act (HR 7724). All of which cover informed consent of human participants in experimental studies. There were a number of influential studies which lead to the establishment of these rules, including the
MIT & Fernald School radioisotope studies, the
Thalidomide Tragedy, Willowbrook
hepatitis study, Milgram's obedience to authority studies.
Observation in natural settings
Survey questionnaires
Longitudinal studies
A
longitudinal study is a 4 September 2007 (UTC)research method which observes a particular population over time. For example, one might wish to study
specific language impairment (SLI) by observing a group of individuals with the condition over a period of time. This method has the advantage of seeing how a condition can affect individuals over long time scales. However, such studies can suffer from attrition due to drop-out or death of subjects. In addition, since individual differences between members of the group are not controlled, it may be difficult to draw conclusions about the populations.
Neuropsychological methods
Neuropsychology involves the study of both healthy individuals and patients, typically who have suffered either
brain injury or
mental illness.
Cognitive neuropsychology and
cognitive neuropsychiatry study neurological or mental impairment in an attempt to infer theories of normal mind and brain function. This typically involves looking for differences in patterns of remaining ability (known as 'functional disassociation's') which can give clues as to whether abilities are comprised of smaller functions, or are controlled by a single cognitive mechanism.
In addition, experimental techniques are often used which also apply to studying the neuropsychology of healthy individuals. These include behavioral experiments, brain-scanning or
functional neuroimaging - used to examine the activity of the brain during task performance, and techniques such as
transcranial magnetic stimulation, which can safely alter the function of small brain areas to investigate their importance in mental operations.
Computational modeling
Computational modeling is a tool often used in
mathematical psychology and
cognitive psychology to simulate a particular behavior using a computer. This method has several advantages. Since modern computers process extremely quickly, many simulations can be run in a short time, allowing for a great deal of statistical power. Modeling also allows psychologists to visualize hypotheses about the functional organization of mental events that couldn't be directly observed in a human.
Several different types of modeling are used to study behavior.
Connectionism uses
neural nets to simulate the brain. Another method is
symbolic modeling, which represents many different mental objects using variables and rules. Other types of modeling include
dynamic systems and
stochastic modeling.
Criticism and controversies
Controversy as a science
A common criticism of psychology concerns its fuzziness as a science. Philosopher
Thomas Kuhn suggested in
1962 that psychology is in a pre-paradigmatic state, lacking the agreement on facts found in mature sciences such as
chemistry and
physics. Because some areas of psychology rely on "
soft" research methods such as surveys and
questionnaires, critics have claimed that psychology is not as scientific as psychologists assume. Methods such as
introspection and
psychoanalysis, used by some psychologists, are inherently
subjective. Objectivity, validity, and rigor are key attributes in science, and some approaches to psychology have fallen short on these criteria. On the other hand, greater use of statistical controls and increasingly sophisticated research design, analysis, and statistical methods, as well as a decline (at least within academic psychology departments) in the use of less scientific methods, have lessened the impact of this criticism to some degree.
Debates continue, however, such as the questioned effectiveness of probability testing as a valid research tool. The concern is that this statistical method may promote trivial findings as meaningful, especially when large samples are used.
[22] Psychologists have responded with an increased use of effect size statistics, rather than sole reliance on the traditional ''p<.05'' decision rule.
In recent years and particularly in the U.S., there has been increasing debate about the nature of therapeutic effectiveness and the relevance of empirical examination for psychotherapy.
[23] One argument states that some therapies are based on discredited theories and are unsupported by empirical evidence of their effectiveness. The other side points to recent research suggesting that all mainstream therapies are of about equal effectiveness, while also arguing that controlled studies often do not take into consideration real-world conditions (e.g. the high co-morbidity rate or the experience of clinicians), that research is heavily biased towards CBT methodologies, and that it typically under-represents minority groups.
Concern about fringe clinical practices
There is also concern from researchers about a perceived gap between scientific theory and its application, in particular with the application of fringe practices. Exponents of evidence-based approaches to clinical psychology practice say that the gap is increasing, and researchers such as Beyerstein (2001) say there has been a large increase in the number of mental health training programs that do not emphasize science training.
[24] According to Lilienfeld (2002) “a wide variety of unvalidated and sometimes harmful psychotherapeutic methods, including
facilitated communication for infantile autism, suggestive techniques for memory recovery (e.g., hypnotic age-regression, guided imagery,
body work), energy therapies (e.g.,
Thought Field Therapy,
Emotional Freedom Technique), and New Age therapies of seemingly endless stripes (e.g.,
rebirthing,
reparenting,
past-life regression,
Primal Scream therapy,
neurolinguistic programming,
alien abduction therapy,
angel therapy) have either emerged or maintained their popularity in recent decades."
[1] Allen Neuringer made a similar point in the field of the experimental analysis of behavior in 1984.
[25] There are some differences of opinion over the actual extent of the research practitioner gap, but the consensus is on the concern about fringe or quack practices, and the legal view favours the use of empirical validation for any psychological intervention (Faigman and Monahan 2005). The emphasis on improvement of evidence based practice has been made in order to increase the general public's confidence in the health professions, and to avoid instances whereby clients forgo evidence based treatments in favour of unvalidated fringe therapies.
See also
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List of basic psychology topics
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List of psychology topics
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Psychologists
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List of publications in psychology
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List of psychologists
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List of psychology organizations
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List of counseling topics
References
1. Omar Khaleefa (Summer 1999). "Who Is the Founder of Psychophysics and Experimental Psychology?", ''American Journal of Islamic Social Sciences'' '16' (2).
2. "Yucologia hoc est de hominis perfectione, anima, ortu", published in Marburg in 1590, was written by the German scholastic philosopher Rudolf Goeckel (1547-1628), who often goes by the Latinized Rudolph Goclenius.
3. Marko Marulić (1450-1524) used the term "psychology" in the title of his Latin treatise "Psichiologia de ratione animae humanae." The treatise itself was not preserved; its title appears in a list of Marulic's works compiled by his younger contemporary, Franjo Bozicevic-Natalis in his "Vita Marci Maruli Spalatensis" (Krstić, 1964).
4. Wilhelm Maximilian Wundt
5. The Principles of Psychology (1890), with introduction by George A. Miller, Harvard University Press, 1983 paperback, ISBN 0-674-70625-0 (combined edition, 1328 pages)
6. Keil, FC. Wilson, RA. (eds) 2001. "The MIT Encyclopedia of the Cognitive Sciences" ''MIT Press'' ISBN 0262731444 p.xx
7. Watson, John B. "Psychology as the Behaviorist Views It" http://psychclassics.yorku.ca/Watson/views.htm
8. Skinner, B.F.: Are Theories of Learning Necessary? http://psychclassics.yorku.ca/Skinner/Theories/
9. www.rso.cornell.edu/scitech/archive/96fal/lang.html
10. Bandura, A. (1973). Aggression: A social learning analysis. Englewood Cliffs, NJ: Prentice-Hall.
Existential-humanist movement
Humanistic psychology was developed in the 1950s in reaction to both behaviorism and psychoanalysis, arising largely from existential philosophy and writers like Jean-Paul Sartre and Søren Kierkegaard. By using phenomenology, intersubjectivity and first-person categories, the humanistic approach seeks to get a glimpse of the whole person and not just the fragmented parts of the personality or cognitive functioning.[Rowan, John. (2001). ''Ordinary Ecstasy : The Dialectics of Humanistic Psychology.'' London, UK : Brunner-Routledge. ISBN 0415236339]
11. Bugental, J. (1964). The Third Force in Psychology. ''Journal of Humanistic Psychology, 4(1)'', 19-25.
12.
[Journal of Clinical Psychology, Volume 60, Issue 12, December 2004 (1203 - 1315), Special Issue: Defining Psychology: Articles and Commentaries on a New Unified Theory (Part 1)]
13.
[Journal of Clinical Psychology, Volume 61, Issue 1, January 2005 (1 - 139), Special Issue: Defining Psychology: Articles and Commentaries on a New Unified Theory (Part 2)]
14.
15. American Psychological Association, Division 12, "About Clinical Psychology"
16. Brain, Christine. (2002). ''Advanced psychology : applications, issues and perspectives.'' Cheltenham : Nelson Thornes. ISBN 0174900589>
17. Leichsenring, Falk & Leibing, Eric. (2003). The effectiveness of psychodynamic therapy and cognitive behavior therapy in the treatment of personality disorders: A meta-analysis. ''The American Journal of Psychiatry, 160(7),'' 1223-1233.
18. Reisner, Andrew. (2005). The common factors, empirically validated treatments, and recovery models of therapeutic change. ''The Psychological Record, 55(3),'' 377-400.
19. Klusman, Lawrence. (2001). Prescribing Psychologists and Patients' Medical Needs; Lessons From Clinical Psychiatry. ''Professional Psychology: Research and Practice, 32(5),'' 496.
20. Industrial and Organization Psychology, Fourth Edition, John Wiley & Sons, Inc., 2006.
21. nasponline.org/about_sp/whatis.aspx
22. Cohen, J. (1994). The Earth is round, p < .05. ''American Psychologist, 49'',.
23. Elliot, Robert. (1998). Editor's Introduction: A Guide to the Empirically Supported Treatments Controversy. ''Psychotherapy Research, 8(2),'' 115.
24. Beyerstein, B. L. (2001). Fringe psychotherapies: The public at risk. The Scientific Re-view of Alternative Medicine, 5, 70–79
25. Neuringer, A.:"Melioration and Self-Experimentation" Journal of the Experimental Analysis of Behavior http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1348111
Further reading
★
Aristotle, Joe Sachs (translator). (350 BCE / 2001) ''On Memory and Recollection'' (''De Memoria et Reminiscentia''). Santa Fe, NM : Green Lion Press. ISBN 1-888009-17-9
★
Bronfenbrenner, U. (1979). ''The Ecology of Human Development''. Cambridge, MA: Harvard University Press. ISBN 0-674-22456-6
★ Chomsky, Noam. (1959).
''A Review of B. F. Skinner's Verbal Behavior''. Language, 35, 26-58.
★ Krstic, K. (1964). Marko Marulic -- The Author of the Term "Psychology." ''Acta Instituti Psychologici Universitatis Zagrabiensis'', no. 36, pp. 7-13. Reprinted at http://psychclassics.yorku.ca/Krstic/marulic.htm
★ Spector, Paul E. "Industrial Organization Psychology." 4th Ed. Australia: John Wiley & Sons, Inc., 2006.
External links
Learning about psychology
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Encyclopedia of Psychology
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Learn Psychology Glossary
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In-Mind, Quarterly Magazine for Social Psychology
History of psychology
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The Archives of the History of American Psychology
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A Century of Psychology (APA)
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Classics in the History of Psychology
Other
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AmoebaWeb Psychology Directory
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