Psychology (ancient Greek: psyche = soul and logos = word) is the study of behaviour, mind and thought. It is largely concerned with humans, although the behaviour and thought of animals is also studied; either as a subject in its own right (see animal cognition and ethology), or more controversially, as a way of gaining an insight into human psychology by means of comparison (see comparative psychology).
Psychology is conducted both scientifically and non-scientifically. 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 follow the classical scientific method. 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. 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.
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.
Psychology differs from sociology, anthropology, economics, and political science, in part, by studying the behaviour of individuals (alone or in groups) rather than the behaviour of the groups or aggregates themselves. 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.
Main article: History of psychology
The end of the 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 Wilhelm Wundt founded the first laboratory dedicated exclusively to psychological research (in Leipzig). Other important early psychologists include Hermann Ebbinghaus (a pioneer in studies on memory), Ivan Pavlov (who 'discovered' the learning process of classical conditioning, and who should be regarded as a physiologist), and Sigmund Freud. Freud's influence has been enormous, though more as cultural icon than a force in (scientific) psychology.
Major nineteenth and twentieth century 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 behaviour 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.
The majority of mainstream psychology is based on a framework derived from cognitive psychology, although the popularity of this paradigm does not exclude others, which are often applied as necessary. Alternatively, a psychologist may specialise in an area in which cognitive psychology is rarely used.
A psychologist will often attempt to measure or test different aspects of psychological function, using psychometric and statistical methods, including well known standardised tests as well as those created as the situation requires.
Academic psychologists may focus purely on research, 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.
Contemporary psychology is broad-based and consists of a diverse set of approaches, subject areas, and applications. A comprehensive list is given in the Topics and Divisions sections below. Where an area of interest is considered to need specific training and specialist knowledge (especially in applied areas), psychological societies 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. While the exact divisions may vary from country to country, the following areas are usually considered as core subjects or approaches by psychology societies and universities.
Cognitive psychology is a framework in which to understand the mind more than a subject area, although it has traditionally focused on certain aspects of psychology. 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.
Clinical and counseling 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. Clinical psychologists largely work within the scientist-practitioner model where clinical problems are formulated as hypotheses to be tested as information is gathered about the patient and his or her mental state. Some clinical psychologists may focus on the clinical management of patients with brain injury. This is known as clinical neuropsychology and typically involves additional training in brain function.
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.
Developmental and 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.
Forensic psychology is concerned with the psychology of crime, criminals, and law enforcement. A forensic psychologist may be involved in assessment of offenders or interventions to prevent offending behaviour, usually with people who have already come in contact with the legal or penal system . Often this involves working with offenders with mental health problems, or with people who act dangerously or in an antisocial manner (for example, psychopaths). Criminal profiling is another important role fulfilled by forensic psychologists and typically involves building psychological profiles of unknown or at-large offenders from the known evidence.
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.
Industrial and organisational psychology
Involved with the application of psychology to the world of business, commerce and the function of organisations, industrial and organisational psychology focuses to varying degrees on the psychology of the workforce, customer, and consumer, including issues such as the psychology of recruitment, training, appraisal, job satisfaction, work behaviour , stress at work and management. Psychologists may also work on product design, interaction with machines or software, advertising, sales, and marketing, to aid functionality, safety and appeal.
Neuropsychology is a branch of psychology that aims to understand how the structure and function of the brain relates to specific psychological processes. Often neuropsychologists are employed as scientists to advance scientific or medical knowledge. Cognitive neuropsychology is particularly concerned with the understanding of brain injury in an attempt to work out normal psychological function. Clinical neuropsychology is the application of neuropsychology for the clinical management of patients with neurocognitive deficits.
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.
Topics in psychology
Although in principle, psychology aims to explain all aspects of thought and behaviour, some topics have generated particular interest, either due to their perceived importance, their ease of study or popularity. Many of the concepts studied by professional psychology stem from the day-to-day psychology used by most people and learnt through experience. This is known as folk psychology to distinguish it from psychological knowledge developed through formal study and investigation. The extent to which folk psychology should be used as a basis for understanding human experience is controversial, although theories that are based on everyday notions of the mind have been among some of the most successful.
For a comprehensive list of psychological topics on wikipedia, please see the list of psychological topics.
Divisions and approaches in psychology
Different disciplines in psychology typically signify both a set of practices and an area of interest. The divisions are largely arbitrary and overlapping (although they may have been formalised into areas of interest by psychological societies or regulatory bodies) and most psychologists will use methods from each area as appropriate, even if they mostly focus on one area of interest in their work.
Some related disciplines
See List of psychologists for a full list of famous and influential psychologists.
See List of publications in psychology for important publications in psychology.