Psychology (from Greek _gr. ψῡχή, "psȳkhē", "breath, life, soul"; and _gr. -λογία, "-logia") is an
academicand 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 knowledgeto various spheres of human activity, including issues related to everyday life (e.g. family, education, and employment) and the treatment of mental healthproblems. Psychologists attempt to understand the role of these functions in individual and social behavior, while also exploring the underlying physiological and neurological processes. Psychology includes many sub-fields of study and application concerned with such areas as human development, sports, health, industry, media, and law.
Philosophical and scientific roots
The study of psychology in a philosophical context dates back to the ancient civilizations of Egypt, Greece, China and India. Psychology began adopting a more clinical [Ibrahim B. Syed PhD, "Islamic Medicine: 1000 years ahead of its times", "Journal of the Islamic Medical Association", 2002 (2), p. 2-9.] and experimental approach under medieval Muslim psychologists and physicians, who built
psychiatric hospitals for such purposes. [Ibrahim B. Syed PhD, "Islamic Medicine: 1000 years ahead of its times", "Journal of the Islamic Medical Association", 2002 (2), p. 2-9 [7-8] . Early practices of ancient psychology included procedures such as lobotomy, which involved removal of specific tissues of the brain believed to cause certain mental problems. Lobotomies were used (though uncommonly) in the medical practices of Egypt, China, and Persia, along with many other ancient civilizations.]
Though the use of psychological
experimentation dates back to Alhazen's " Book of Optics" in 1021,Omar Khaleefa (Summer 1999). "Who Is the Founder of Psychophysics and Experimental Psychology?", "American Journal of Islamic Social Sciences" 16 (2).] Bradley Steffens (2006). "Ibn al-Haytham: First Scientist", Chapter 5. Morgan Reynolds Publishing. ISBN 1599350246.] psychology as an independent experimental field of study began in 1879, when Wilhelm Wundtfounded the first laboratory dedicated exclusively to psychological research at Leipzig Universityin Germany, for which Wundt is known as the "father of psychology". [ [http://plato.stanford.edu/entries/wilhelm-wundt/ Wilhelm Maximilian Wundt] ] 1879 is thus sometimes regarded as the "birthdate" of psychology. The American philosopher William Jamespublished his seminal book, " Principles of Psychology", [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)] in 1890, while 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 memoryat the University of Berlin; and the Russian physiologist Ivan Pavlov(1849-1936), who investigated the learningprocess now referred to as classical conditioning.
During the 1890s, the
Austrian physician Sigmund Freuddeveloped a method of psychotherapyknown as psychoanalysis. Freud's understanding of the mind was largely based on interpretive methods, introspectionand clinical observations, and was focused in particular on resolving unconscious conflict, mental distress and psychopathology. Freud's theories became very well-known, largely because they tackled subjects such as sexuality, repression, and the unconscious mindas general aspects of psychological development. These were largely considered taboosubjects at the time, and Freud provided a catalyst for them to be openly discussed in polite society. Freud also had a significant influence on Carl Jung, whose analytical psychologybecame an alternative form of depth psychology. Philosopher Karl Popperargued that Freud's psychoanalytic theories were presented in untestable form.Karl Popper, Conjectures and Refutations, London: Routledge and Keagan Paul, 1963, pp. 33-39; from Theodore Schick, ed., Readings in the Philosophy of Science, Mountain View, CA: Mayfield Publishing Company, 2000, pp. 9-13. [http://faculty.washington.edu/lynnhank/Popper.doc] ] Due to their subjective nature, Freud's theories are often of limited interest to many scientifically-oriented psychology departments. Followers of Freud who accept the basic ideas of psychoanalysis but alter it in some way are called neo-Freudians. Modification of Jung's theories has led to the archetypal and process-oriented schools of psychological thought.
John B. Watsonand embraced and extended by Edward Thorndike, Clark L. Hull, Edward C. Tolman, and later B.F. Skinner, behaviorismgained popularity as a guiding psychological theory during the early decades of the 20th century. Its development was partly due to the success of laboratory based animal experimentation and partly in reaction to Freudian psychodynamics which tended to rely on case studies and clinical experience. Freud's theories and practice focused on the resolution unconscious conflict often arising from childhood experiences to treat psychological trauma and psychosis. However, it was argued that Freud's theories were difficult to test empirically.
Behaviorism differs from other perspectives in a number of ways. Behaviorists focus on behavior-environment relations and analyze overt and covert (i.e., private) behavior as a function of the organism interacting with its environment [Skinner, B.F. (1974). About Behaviorism. New York: Random House] . Behaviorists do not reject the study of covert or private events (e.g., dreaming). What behaviorists reject is an autonomous causal entity inside the organism that causes overt (e.g., walking, talking) or covert (e.g., dreaming, imagining) behavior. Concepts such as "mind" or "consciousness" are not used by behaviorists because such terms do not describe actual psychological events (such as imagining) but are used as explanatory entities hidden somewhere in the organism. By contrast, behavorism treats private events as behavior, and analyzes them in the same way as overt behavior (hence the name "behaviorism"). Behavior refers to the concrete events of the organism, overt or private. Furthermore, the focus on behavior-environment relations does not neglect the importance of genes or biology in relation to behavior. Rather, the study of behavior-environment relations provides a powerful tool to examine the effects of these and other variables. Skinner was also a proponent of introspection in the sense that he felt it could be used to point to environmental variables of which behavior (overt and covert) is a function (Skinner, 1974). To Skinner, however, what was "spected" in introspection was not mental phenomena, but the organisms physical body. Other behaviorists before Skinner had differing views regarding these matters. For instance, in "Psychology as the Behaviorist Views It" (1913), [Watson, John B. "Psychology as the Behaviorist Views It" http://psychclassics.yorku.ca/Watson/views.htm] 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 research method, considering it to be too conducive to speculative theories that may desensitize the researcher to interesting and unanticipated happenings in his experiments. [Skinner, B.F.: Are Theories of Learning Necessary? http://psychclassics.yorku.ca/Skinner/Theories/ ]
Behaviorism was the dominant paradigm in American psychology throughout the first half of the 20th century. However, the modern field of psychology is largely dominated by
cognitive psychology. Linguist Noam Chomsky's 1959 review of B. F. Skinner's Verbal Behavior challenged the behaviorist approaches to studies of behavior and language dominant at the time and contributed to the cognitive revolutionin psychology. Chomsky was highly critical of what he considered arbitrary notions of 'stimulus', 'response' and 'reinforcement' which Skinner borrowed from animal experiments in the laboratory. Chomsky argued that Skinner's notions could only be applied to complex human behavior, such as language acquisition, in a vague and superficial manner. Chomsky emphasized that research and analysis must not ignore the contribution of the child in the acquisition of language and proposed that humans are born with a natural ability to acquire language.Chomsky, N. A. (1959), [http://www.chomsky.info/articles/1967----.htm A Review of Skinner's Verbal Behavior] ] Work most associated with psychologist Albert Bandura, who initiated and studied social learning theory, showed that children could learn aggression from a role model through observational learning, without any change in overt behavior, and so must be accounted for by internal processes. [Bandura, A. (1973). Aggression: A social learning analysis. Englewood Cliffs, NJ: Prentice-Hall.]
Existentialism and humanism
Humanistic psychologywas developed in the 1950s in reaction to both behaviorism and psychoanalysis, arising largely from the existentialphilosophy of writers such as Jean-Paul Sartreand Søren Kierkegaard. By using phenomenology, intersubjectivity and first-person categories, the humanistic approach seeks to glimpse the whole person--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] Humanism focuses on uniquely human issues and fundamental issues of life, such as self-identity, death, aloneness, freedom, and meaning. There are several factors which distinguish the Humanistic Approach from other approaches within psychology, including the emphasis on subjective meaning, a rejection of determinism, and a concern for positive growth rather than pathology. Some of the founding theorists behind this school of thought were Abraham Maslowwho formulated a hierarchy of human needs, Carl Rogerswho created and developed Client-centered therapy, and Fritz Perlswho helped create and develop Gestalt therapy. It became so influential as to be called the "third force" within psychology (along with behaviorism and psychoanalysis). [Bugental, J. (1964). The Third Force in Psychology. "Journal of Humanistic Psychology, 4(1)", 19-25.]
As computer technology proliferated, so emerged 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. Cognitive psychology differs from other psychological perspectives in two key ways. First, it accepts the use of the scientific method, and generally rejects introspection as a method of investigation, unlike symbol-driven approaches such as Freudian psychodynamics. Second, it explicitly acknowledges the existence of internal mental states (such as belief, desire and motivation), whereas behaviorism does not.
brainand nervous systemfunction also became understood, partly due to the experimental work of people such as Charles Sherringtonand Donald Hebb, and partly due to studies of people with brain injury(see cognitive neuropsychology). With the development of technologies for measuring brain function, neuropsychologyand cognitive neurosciencehave become increasingly active areas of contemporary psychology. Cognitive psychology has been subsumed along with other disciplines, such as philosophy of mind, computer science, and neuroscience, under the umbrella discipline of cognitive science.
chools of thought
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. On the basis of Tinbergen's four questionsa framework of reference of all fields of psychological research can be established (including anthropological research and humanities).
In modern times, psychology has adopted an integrated perspective towards understanding consciousness, behavior, and social interaction. This perspective is commonly referred to as the
biopsychosocialapproach. The basic tenet of the biopsychosocial model is that any given behavior or mental process affect and are affected by dynamically interrelated biological, psychological, and social factors. [cite book
last = Richard Frankel, Timothy Quill, Susan McDaniel
title = The Biopsychosocial Approach: Past, Present, Future
publisher = Boydell & Brewer
date = 2003
isbn = 1580461026, 9781580461023 ]
The "psychological" aspect refers to the role that cognition and emotions play in any given psychological phenomenon. For example, the effect of mood or beliefs and expectations on an individual's reactions to an event. The "biological" aspect refers to the role that biological factors (such as genetic variability or brain function and development) play in a psychological phenomenon. For example, the effect that the prenatal environment and brain development may have on an individual's future cognitive ability. The "socio-cultural" aspect refers to the role that social and cultural environments play in a given psychological phenomenon. For example, the role of parental or peer influence in the behaviors or characteristics of an individual.
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. A comprehensive list of the sub-fields and areas within psychology can be found at the
list of psychological topicsand list of psychology disciplines.
Abnormal psychologyis the study of abnormal behavior in order to describe, predict, explain, and change abnormal patterns of functioning. Abnormal psychology studies the nature of psychopathologyand its causes, and this knowledge is applied in clinical psychologyto treat a patient 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 is the scientific study of the biological bases of behavior and mental states. Because all behavior is controlled by the nervous system, it is sensible to study how the
brainfunctions 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 to observe which areas of the brain are active during a particular task.
Cognitive psychologystudies cognition, the mental processes underlying behavior. It uses information processingas a framework for understanding the mind. Perception, learning, problem solving, memory, attention, languageand emotionare all well researched areas. Cognitive psychology is associated with a school of thought known as cognitivism, whose adherents argue for an information processingmodel of mental function, informed by positivismand experimental psychology.
On a broader level,
Cognitive scienceis a conjoined enterprise of cognitive psychologists, neurobiologists, workers in artificial intelligence, logicians, linguists, and social scientists, and places a slightly greater emphasis on computational theory and formalization. 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 psychologyrefers 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 cognitionand 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 neuroscienceand social neuroscience).
Counseling psychologyseeks to facilitate 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, and community mental health centers.
Clinical psychologyincludes 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. 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.Brain, Christine. (2002). "Advanced psychology: applications, issues and perspectives." Cheltenham: Nelson Thornes. ISBN 0174900589>] 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. [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.] [Reisner, Andrew. (2005). The common factors, empirically validated treatments, and recovery models of therapeutic change. "The Psychological Record, 55(3)," 377-400.] Because of this, more training programs and psychologists are now adopting an eclectic therapeutic orientation.
Mainly focusing on the development of the human mind through the life span,
developmental psychologyseeks 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 agingand processes throughout the life span, especially at other times of rapid change (such as adolescence and old age). Developmental psychologists draw on the full range of theorists in scientific psychology to inform their research.
Educational psychologyis 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 Piagetand Jerome Brunerhas been influential in creating teachingmethods and educational practices.
Forensic psychologycovers a broad range of practices primarily involving clinical evaluations of defendants, reports to judges and attorneys, and courtroom testimony on given issues. Forensic psychologists are appointed by the court to conduct competency to stand trial evaluations, competency to be executed evaluations, sanity evaluations, involuntary commitment evaluations, provide sentencing recommendations, and sex offender evaluation and treatment evaluations and provide recommendations to the court through written reports and testimony. Most of the questions the court asks the forensic psychologist are not questions of psychology but rather legal questions. For example, there is no definition of sanity in psychology. Rather, sanity is a legal definition that varies from state to state in the United States and from jurisdiction to jurisdiction. Therefore, a prime qualification of a forensic psychologist is an intimate understanding of the law, especially criminal law.
Health psychologyis the application of psychological theory and research to health, illness and health care. Whereas clinical psychology focuses on mental health and neurological illness, health psychologyis 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 lifeand in research into the psychological impact of health and social care.
Human factors psychology
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(I/O) applies psychological concepts and methods to optimize human potential in the workplace. Personnel psychology, a subfield of I/O psychology, applies the methods and principles of psychology in selecting and evaluating workers. I/O psychology's other subfield, organizational psychology, examines the effects of work environments and management styles on worker motivation, job satisfaction, and productivity. [Myers (2004). Motivation and work. "Psychology". New York, NY: Worth Publishers]
Personality psychologystudies enduring psychological patterns of behavior, thoughtand 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 Cattellproposed 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.
Psychology and Law
Psychology and law(or 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.
Quantitative psychologyinvolves 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 loosely covers the longer standing subfields psychometricsand mathematical psychology. Psychometricsis 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.
psychometricsis mainly concerned with individual differencesand population structure, mathematical psychologyis concerned with modeling of mental and motor processes of the average individual. Psychometricsis more associated with educational psychology, personality, and clinical psychology. Mathematical psychologyis more closely related to psychonomics/experimental and cognitive, and physiological psychologyand (cognitive) neuroscience.
Social psychology is the study of the nature and causes of human social behavior and mental processes, 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, social psychologists study 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 cognitionis a common approach and involves a mostly cognitive and scientific approach to understanding social behavior.
School psychologycombines principles from educational psychologyand clinical psychologyto understand and treat students with learning disabilities; to foster the intellectual growth of "gifted" students; to facilitate prosocial behaviours in adolescents; and otherwise to promote safe, supportive, and effective learning environments. School psychologists are trained in educational and behavioral assessment, intervention, prevention, and consultation, and many have extensive training in research. [cite web|url=http://nasponline.org/about_sp/whatis.aspx|title=National Association of School Psychologists|accessdate=June 1|accessyear=2008] 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 degreeas 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 in experimental 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 knowledge from other fields to help explain and understand psychological phenomena. Qualitative psychological researchutilizes 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 psychologyis more typically pursued via 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 psychologyto deploy such knowledge for immediate and practical benefit. These approaches are not mutually exclusive, and many psychologists will be involved in both researching and applying psychology at some point during their career. Many clinical psychology programs aim to develop in practicing psychologists both knowledge of and experience with research and experimental methods, which they may interpret and employ as they treat individuals with psychological issues.
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.
Experimental psychological research is conducted in a laboratory under controlled conditions. This method of research relies on the application of the
scientific methodto understand behavior. Experimenters 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, psychophysiologyand 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
Experiments on humans have been put under some controls; namely informed and voluntary consent. After WWII, the
Nuremberg Codewas established, because of Nazi abuses of experimental subjects. Later, most countries (and scientific journals) adopted the Declaration of Helsinki. In the US, the NIHestablished 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 ThalidomideTragedy, Willowbrook hepatitisstudy, Milgram's obedience to authority studies.
at a time, which is why animals used for experiments are housed in laboratory settings. In contrast, human environments and genetic backgrounds vary widely, which makes it difficult to control important variables for human subjects. [cite web|url=http://www.ncabr.org/biomed/FAQ_animal/faq_animal_8.html |title=Ncabr.Org : About Biomedical Research : Faq |accessdate=2008-07-01]
Qualitative and descriptive research
Research designed to answer questions about the current state of affairs such as the thoughts, feelings and behaviors of individuals is known as descriptive research. One distinction that is made in descriptive research concerns whether it is qualitative or quantitative in orientation. Qualitative research is descriptive research that is focused on observing and describing events as they occur, with the goal of capturing all of the richness of everyday behavior and with the hope of discovering and understanding phenomena that might have been missed if only more cursory examinations have been made.
Observation in natural settings
In the same way
Jane Goodallstudied the role of chimpanzeesocial and family life, psychologists conduct similar observational studies in human social, professional and family lives. Sometimes the participants are aware they are being observed and other times it is covert; the participants do not know they are being observed. Ethical guidelines need to be taken into consideration when covert observation is being carried out.
Statistical surveys are used in psychology for measuring attitudes and traits, monitoring changes in mood, or checking the validity of experimental manipulations. Most commonly, psychologists use paper-and-pencil surveys. However, surveys are also conducted over the phone or through e-mail. Increasingly, web-based surveys are being used in research. [cite web|url=http://www.happypsych.com|title=Paths to Happiness Survey - happiness study|accessdate=June 1|accessyear=2008 Accessed
2007-11-02.] Similar methodology is also used in applied setting, such as clinical assessment and personnel assessment.
longitudinal studyis a 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.Longitudinal study is a developmental research strategy that involves testing an age group repeatedly over many years. Longitudinal studies answer vital questions about how people develop. This developmental research follows people over years and the outcome has been an incredible array of findings, especially relating to psychological problems.
Neuropsychologyinvolves the study of both healthy individuals and patients, typically who have suffered either brain injuryor mental illness. Cognitive neuropsychologyand cognitive neuropsychiatrystudy 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 [ Ron Sun, (2008). The Cambridge Handbook of Computational Psychology. Cambridge University Press, New York. 2008. ] is a tool often used in
mathematical psychologyand cognitive psychologyto 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.
Connectionismuses neural networks 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 systemsand stochastic modeling.
Criticism and controversies
tatus as a science
A common criticism of psychology concerns its fuzziness as a science. Philosopher
Thomas Kuhn's 1962 critique implied psychology overall was in a pre-paradigm state, lacking the agreement on overarching theory found in mature sciences such as chemistryand physics. Because some areas of psychology rely on research methods such as surveys and questionnaires, critics have claimed that psychology is not as scientific as many assume. Other phenomena that psychologists are interested in such as personality, thinkingand emotioncannot be directly measured and often rely on subjectiveself-report which is considered inherently unreliable.
The validity of probability testing as a research tool has been called into question. There is concern that this statistical method may promote trivial findings as meaningful, especially when large samples are used. [Cohen, J. (1994). The Earth is round, p < .05. "American Psychologist, 49".] Some psychologists have responded with an increased use of
effect sizestatistics, rather than sole reliance on the traditional "p<.05" decision rule in statistical hypothesis testing.
In recent years, and particularly in the U.S., there has been increasing debate about the nature of therapeutic effectiveness and about the relevance of empirically examining psychotherapeutic strategies. [Elliot, Robert. (1998). Editor's Introduction: A Guide to the Empirically Supported Treatments Controversy. "Psychotherapy Research, 8(2)," 115.] One argument states that some therapies are based on discredited theories and are unsupported by empirical evidence. 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 the methods of the cognitive behavioral therapies (CBT); 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 esoteric 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.Beyerstein, B. L. (2001). Fringe psychotherapies: The public at risk. The Scientific Re-view of Alternative Medicine, 5, 70–79] According to Lilienfeld (2002) “a wide variety of unvalidated and sometimes harmful psychotherapeutic methods, including
psychoanalysis, facilitated communicationfor 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) have either emerged or maintained their popularity in recent decades." [cite web|url=http://www.srmhp.org/0101/raison-detre.html |title=SRMHP: Our Raison d’Être |accessdate=2008-07-01] Allen Neuringer made a similar point in the field of the experimental analysis of behavior in 1984. [Neuringer, A.:"Melioration and Self-Experimentation" Journal of the Experimental Analysis of Behavior http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=1348111] 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.
List of basic psychology topics
List of psychologists
List of psychology organizations
List of psychology topics
List of publications in psychology
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