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Psychology (Classical
Greek: psyche = "soul" or "mind", logos = "study
of") is an academic
and applied
field involving the study of
behavior
and its relationship to the mind and brain.
Psychology also refers to the application of such knowledge
to various spheres of human activity, including problems of
individuals' daily lives and the treatment of mental
illness. It is largely concerned with humans, although the
behavior and mental processes of animals
is also be part of psychological research, either as a subject in
its own right (e.g. animal
cognition and ethology),
or as a way of gaining an insight into human psychology by
means of comparison (including comparative
psychology). Psychology is commonly defined as the science of
behavior and mental processes. Although its name derives from
Greek word "psyche", psychology does not scientifically study the
soul.
Psychology differs from sociology,
anthropology,
economics,
and political
science, in part, because it involves studying the behaviour of
individuals (alone or in groups) rather than the behavior of the
groups or aggregates themselves. Psychology differs from biology
and neuroscience
in that it is primarily concerned with the overall behavior of a
system, and not simply the pattern of neural responses produced by
the system.
Although psychological questions were asked in antiquity (see Aristotle's
De Memoria et Reminiscentia or "On Memory and
Recollection"), psychology emerged as a separate discipline only
recently. The first person to call himself a "psychologist", Wilhelm
Wundt, opened the first psychological laboratory in 1879.
History
Main article: History
of psychology
The late 19th
century marks the start of psychology as a scientific
enterprise. The year 1879 is
commonly seen as the start of psychology as an independent field of
study, because in that year German
scientist
Wilhelm
Wundt founded the first laboratory dedicated exclusively to
psychological research in Leipzig,
Germany.
Other important early contributors to the field include Hermann
Ebbinghaus (a pioneer in studies on memory),
the Russian
Ivan
Pavlov (who discovered the learning process of classical
conditioning), and the Austrian
Sigmund
Freud. Freud's influence has been enormous, though more as
cultural icon than a force in (scientific) psychology. Freud's basic
theories postulated the existence in humans of various unconscious
and instinctive "drives", and that the "self" existed as a perpetual
battle between the desires and demands of the internal id,
ego, and superego.
The mid-20th century saw a rejection of Freud's theories among
many psychologists as being too unscientific, as well as a reaction
against Edward
Titchener's abstract approach to the mind. This led to the
formulation of behaviorism
by John
B. Watson, which was popularized by B.F.
Skinner. Behaviorism proposed epistemologically
limiting psychological study to overt behavior, since that could be
quantified and easily measured. Scientific knowledge of the "mind" was
considered too metaphysical,
hence impossible to achieve. The final decades of the 20th century
have seen the rise of a new interdisciplinary approach to studying
human psychology, known collectively as cognitive
science. Cognitive science again considers the "mind" as a
subject for investigation, using the tools of evolutionary
psychology, linguistics,
computer
science, philosophy,
and neurobiology.
This new form of investigation has proposed that a wide
understanding of the human mind is possible, and that such an
understanding may be applied to other research domains, such as artificial
intelligence.
Principles of psychology
Mind and brain
Psychology does not necessarily refer to the brain or
nervous
system and can be framed purely in terms of phenomenological
or information
processing theories of mind. Increasingly, though, an
understanding of brain function is being included in psychological
theory and practice, particularly in areas such as artificial
intelligence, neuropsychology,
and cognitive
neuroscience.
Schools 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. See psychological
schools of thought for a comprehensive list.
Scope of psychology
Psychology is an extremely broad field, and it encompasses
many different approaches to the study of behavior. Below are the
major areas of inquiry that comprise psychology. A
comprehensive list of the sub-fields and areas within
psychology is given in the Related Topics section below.
Biological basis: the brain
Main articles: Behavioral
neuroscience, Cognitive
neuroscience, Neuropsychology
Since all behavior is rooted in the brain, 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 psychological processes. Often neuropsychologists
are employed as scientists to advance scientific or medical
knowledge. Neurospychology 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 brain
imaging tools, such as fMRI, to
observe which areas of the brain are active during a particular
behavioral task.
Information processing: the mind
Main articles: Cognitive
psychology, Cognitive
science
The nature of thought
is another core interest in psychology. Cognitive
psychology is primarily concerned with the process by which perception
results in behavior. Cognitive
psychology 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 based on a
school of thought known as cognitivism,
whose adherents argue for an information
processing model of mental function, informed by positivism
and experimental
psychology. Techniques and models from cognitive psychology are
widely applied and form the mainstay of psychological theories in
many areas of both research and applied 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 used computational
models to simulate phenomena of interest. Since mental events
cannot directly be observed, computational models provide a tool for
studying the functional organization of the brain and behavior. Such
models allow cognitive psychologists to better understand the
information processing requirements of behavior and explain
hypotheses obtained from behavioral experiments.
Change over time: development
Main articles: Developmental
psychology, Educational
psychology
Largely 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 perceptions
change as we age. This may focus on intellectual, cognitive, neural,
social, or moral development. Researchers who study children use a
number of unique research methods to engage them in experimental
tasks. These tasks often resemble specially designed games and
activities that are both enjoyable for the child and scientifically
useful. In addition to studying children, developmental
psychologists also study other times of rapid change (such as
adolescence and old age).
Educational
psychology largely seeks to apply much of this knowledge and
understand how learning can best take place in educational
situations. Because of this, the work of child psychologists such as
Lev
Vygotsky, Jean
Piaget and Jerome
Bruner has been influential in creating teaching
methods and educational practices.
Mental health
Main articles: Clinical
psychology, Health
psychology
Clinical
psychology is the application of psychology to the
understanding, treatment, and assessment of psychopathology,
behavioural or mental health issues. It has traditionally been
associated with counselling
and psychotherapy,
although modern clinical psychology may take an eclectic approach,
including a number of therapeutic approaches. Typically, although
working with many of the same clients as psychiatrists,
clinical psychologists do not prescribe psychiatric drugs. Some
clinical psychologists may focus on the clinical management of
patients with brain
injury. This area is known as clinical
neuropsychology.
In recent years and particularly in the United States, a major
split has been developing between academic research psychologists in
universities and some branches of clinical psychology. Many academic
psychologists believe that these clinicians use therapies based on
discredited theories and unsupported by empirical evidence of their
effectiveness. From the other side, these clinicians believe that
the academics are ignoring their experience in dealing with actual
patients. The disagreement has resulted in the formation of the American
Psychological Society by the research psychologists as a new
body distinct from the American
Psychological Association.
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 behaviour 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 or in research into the psychological impact of health
and social care.
Interaction with others
Main articles: Social
psychology, Personality
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 behaviour
(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 behaviour.
Personality
psychology includes theories of career
development.
Applied psychology
Main articles: Applied
psychology, Industrial
and organizational psychology, Human
factors, Forensic
psychology
The basic premise of applied psychology is the use of
psychological principles and theories to overcome
practical problems in other fields, such as business
management, product
design, ergonomics,
nutrition,
and clinical
medicine. Applied
psychology includes the areas of industrial/organizational
psychology, human
factors, forensic
psychology, as well as many other areas.
Industrial and organizational
Industrial
and organizational psychology focuses to varying degrees on the
psychology of the workforce, customer, and consumer, including
issues such as the psychology of recruitment, selecting employees
from an applicant pool which overall includes training, performance
appraisal, job satisfaction, work
behaviour, stress at
work and management.
Forensic psychology
Forensic
psychology is the area concerned with the application of
psychological methods and principles to legal questions and issues.
Most typically, this involves a clinical analysis of a particular
individual and an assessment of some specific psycho-legal question.
Forensic psychology refers to any application of psychological
principles, methods or understanding to legal questions or issues.
In addition to the applied practices, it also includes academic or
empircal research on topics involving law and human behavior.
Human factors
Human
factors 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 is to better
design objects by taking into account the limitations and biases of
human behavior.
Research methods
Psychology is conducted both scientifically and
non-scientifically, but is to a large extent wholly rigorous.
Mainstream psychology is based largely on positivism,
using quantitative
studies and the scientific
method to test and disprove hypotheses,
often in an experimental
context. Psychology tends to be eclectic, drawing on scientific
knowledge from other fields to help explain and understand
behaviour. However, not all psychological research
methods strictly follow the empirical positivism philosophy. Qualitative
research utilizes interpretive techniques and is descriptive in
nature, enabling the gathering of rich clinical information
unattainable by classical experimentation. Some psychologists,
particularly adherents to humanistic
psychology, may go as far as completely rejecting a scientific
approach, viewing psychology more as an art rather than a rigid
science. However, mainstream psychology has a bias towards the scientific
method, which is reflected in the dominance of cognitivism
as the guiding theoretical
framework used by most psychologists to understand thought and
behaviour.
The testing
of different aspects of psychological function is a significant area
of contemporary psychology. Psychometric
and statistical
methods predominate, including various well-known standardised 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 work. Clinical psychology,
among many of the various discipline 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 individual with
psychological issues or use psychology to help others.
Where an area of interest is considered to need specific training
and specialist knowledge (especially in applied areas),
psychological associations will typically set up 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 article: Experimental
psychology
The majority of psychological research is conducted in the
laboratory
under controlled conditons. This method of research relies
completely on the scientific method to determine the basis of
behavor. Common measurements of behavior include reaction
time and various psychometric
measurements. Experiments are conducted to test a particular hypothesis.
As an example of a psychological experiment, one may want to test
people's perception of different tones.
Specifically, one could ask the following question: is it easier for
people to discriminate one pair of tones from another depending upon
their frequency? To answer this, one would want to disprove the
hypothesis that all tones are equally discriminable, regardless of
their frequency. (See hypothesis
testing for an explanation of why one would disprove a
hypothesis rather than attempt to prove one.) A task to test this
hypothesis would have a participant seated in a room listening to a
series of tones. If the participant would make one indication (by
pressing a button, for example) if they thought the tones were two
different sounds, and another indication if they thought they were
the same sound. The proportion of correct responses would be the
measurement used to describe whether or not all the tones were
equally discriminable. The result of this particular experiment
would probably indicate better discrimination of certain tones based
on the human threshold
of hearing.
Correlational studies
A correlational
study uses statistics
to determine if one variable is likely to co-occur with another
variable. For example, one might be interested in whether or not an
individual smokes is correlated with their change of getting lung
cancer. One way to answer this would be to simply take a group of
people who smoke and measure the proportion of those that get lung
cancer within a certain time. In this particular case, one would
probably find a high correlation (since tobacco has a deletarious
effect on the lungs). However, we cannot know for certain that
smoking is the cause of lung cancer. It could be that those
more prone to cancer are also more likely to take up smoking. A
third alternative is that some other variable caused both conditons.
This is a major limitation of correlational studies, and it is
exemplified by the fact that correlation
does not imply causation.
Longitudinal studies
A longitudinal
study is 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, since individual differences between members
of the group are not controlled, it may be difficult to draw
conclusions about the populations.
Neuropsychological methods
Computational modeling
Compuational
modeling is a tool often used in cognitive
psychology to simulate a particular behavior using a computer.
This method has several advantages. Since modern computers are
extremely fast, many simulations can be run in a short time,
allowing for a great deal of statistical power. Modeling also allows
psychologists to visualise 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 different mental objects using
variables and rules. Other types of modeling include dynamic
systems and stochastic
modeling.
Criticisms of psychology
Psychology has always been a controversial discipline. Some
criticisms of psychology have been made on ethical and philosophical
grounds. Some have argued that by subjecting the human mind to
experimentation and statistical study, psychologists objectify
persons. Because it treats human beings as things, as objects that
can be examined by experiment, psychology is sometimes portrayed as
dehumanizing. It has been argued that ultimately, quantitative
psychological research ignores or downplays what is most essential
about being human.
Another common criticism of psychology concerns its fuzziness as
a science. Since it relies on "soft" methods such as statistical
analysis and questionnaires, some have said, psychology is not as
scientific as it claims to be. Many believe that the mind is not
amenable to quantitative scientific research, and as support for
their criticism cite the vast theoretical diversity of psychology, a
discipline which agrees on very little about how the mind works.
This criticism, however, cannot be applied universally to
psychology, as some areas within the discipline, such as behaviorism
or neuropsychology, advocate only the scientific method. In
defending their discipline, psychologists will often point out that
astronomy's claim to being a science is also open to argument
because it's theories are largely untestable, being only open to
observation (philosophically, a theory must be testable and able to
be proven false for it to be scientific). This criticism does not
reflect the vast majority of the type of research conducted in
modern psychology.
Related topics
For a comprehensive list of psychological topics on wikipedia,
please see the list
of psychological topics. See List
of psychologists for a full list of famous and influential
psychologists. See List
of publications in psychology for important publications in
psychology.
Areas related to psychology:
External links
Psychology Resources
Psychology Societies
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