Psychology – the Science of Emotion, Personality, Behavior


Psychology, is both and academic and applied domain that encompasses the scientific study of mental processes and behavior. Psychologists endeavor to disentangle the working of the brain as subjected to a pragmatic life with a human entity as a frame of reference as well as the self, psychologists study trends such as perception, cognition, emotion, personality, behavior, and interpersonal relationships.

Psychology consequently, refers to the implementation of the same knowledge to various spheres oh human activities, including issues related to daily life, that include family, education, and work; and the treatment go abroad of mental health problems. Into the bargain of breaking down the brain’s performance of fundamental mental functional, psychology also endeavors to comprehend the role of those functions play in social behaviour and in social dynamics, while incorporating the underlying physiological and neurological processes into its conceptions of mental functioning.


From research findings it has been established that the use of psychological experimentation dates back to 1021, as an independent experimental field of study, it commenced in the 1879, when Wilhelm Wundt founded the first laboratory that was entered strictly on psychological research at Leipzig University in German. Significant contributors in the domain of psychology include Hermann Ebbinghaus (1850-1909), Ivan Pavlov (1849-1936), who investigated the process of learning popularly known as the 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, introspection and clinical observations, and was focused in particular on resolving unconscious conflict, mental distress and psychopathology. Freud’s hypothesis became popular, principally because they embarked upon issues such as sexuality, repression, and the unconscious mind in broad spectrum of psychological development.

These were largely considered outlawed subjects at the time, and Freud provided a mechanism for them to be openly discussed in polite society. Many of Freud’s ideas have remained very influential in clinical work and other areas of psychology. Freud divided mind into the conscious mind or Ego and two parts of the Unconscious: the Id (Latin for “IT”, or instincts and the Superego. Keil, FC. Wilson, RA.(2001).

He used the idea of the unconscious in order to explain certain kinds of neurotic behavior. But, Karl Popper (2000), argued that Freud’s psychoanalytic theories were presented in untestable form. Due to their subjective nature, Freud’s theories are of limited (typically chronological) interest to modern academic psychology departments. 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 psychodynamics, 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, Clark L. Hull, Edward C. Tolman, and B.F. Skinner (2001), 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. They doubted the validity of introspection for studying internal mental states such as feelings, sensations, beliefs, desires, and other unobservable.

In “Psychology as the Behaviorist Views It”, 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 Skinner, B.F.(2004), 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.

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. Chomsky, Noam. (1959), helped spark the cognitive revolution in psychology through his review of Skinner, B.F. (2004), Verbal Behavior, in which Chomsky, Noam. (1959), challenged the behaviorist approach to the study of behavior and language dominant in the 1950s.

In his theory of Generative Grammar Chomsky, Noam. (1959), 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 internal states of mind must be studied within the realm of science. Similarly, work by Albert Bandura (2001), showed that children could learn by social observation, without any change in overt behavior, and so must be accounted for by internal representations. Elliot, Robert. (1998).

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 Siren Kierkegaard (2001). By using phenomenology, inter subjectivity 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.

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, Brain, Christine. (2002), who created and developed Client-centered therapy, and Fritz Perls who helped create and develop Gestalt therapy. It became as influential as to be called the “third force” within psychology (preceded by behaviorism and psychoanalysis). Elliot, Robert. (1998).


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 understood, partly due to the experimental work of people such as Charles Sherrington and Donald Hebb (1999), 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.


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. Aristotle, Joe Sachs (2001).

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.


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. Leichsenring, Falk & Leibing, Eric. (2003).

Fields of research

Qualitative psychological research and Quantitative psychological 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

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 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

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. Leichsenring, Falk & Leibing, Eric. (2003). 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 neurophysiologists 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. Leichsenring, Falk & Leibing, Eric. (2003).

Cognitive 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 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. Leichsenring, Falk & Leibing, Eric. (2003).

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). Beyerstein, B. L. (2001).

Developmental psychology

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).

Personality psychology

Personality psychology studies enduring psychological patterns of behavior, thought and emotion, commonly called an individual’s personality. 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 has 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 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:

  • the construction of instruments and procedures for measurement;
  • 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. Beyerstein, B. L. (2001).

Mathematical psychology is more closely related to psychonomics/experimental and cognitive, and physiological psychology and (cognitive) neuroscience. Beyerstein, B. L. (2001).

Social 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. Leichsenring, Falk & Leibing, Eric. (2003).

Fields of application

Applied psychology encompasses both psychological researches 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

Clinical psychology includes the study and application of psychology for the purpose of understanding, preventing, and relieving psychologically-based distress or Psychological testing psychological assessment and psychotherapy, although clinical psychologists may also engage in research, teaching, consultation, forensic testimony, and program development and administration. 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. Leichsenring, Falk & Leibing, Eric. (2003).

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. Miller, G.A. (2003).

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. 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.

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

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, and community mental health centers.

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.

Forensic psychology

Forensic psychology covers a broad range of practices primarily involving 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. Bronfenbrenner, U. (1979), 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 psychology is an intimate understanding of the law, especially criminal law.

Psychology and Law

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

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. Watson, John B.(2002)

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. Watson, John B.(2002)

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, (2000) Industrial Psychology became recognized as a legitimate part of the social science.

Organizational Psychology was not officially added until the 1970s and since then, the field has flourished. Watson, John B.(2002) 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 Psychological 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

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. Watson, John B.(2002) They are trained to be experts in educational and behavioral assessment, intervention, prevention, and consultation, and many have extensive training in research.

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. Watson, John B.(2002) 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, ethnography, 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. Keil, FC. Wilson, RA. (2001). 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 psychologist’s 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. Keil, FC. Wilson, RA. (2001)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

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). Keil, FC. Wilson, RA. (2001)

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. Pavlov Museum, (2005). 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. Pavlov Museum, (2005).

Animal studies

One of Pavlov’s dogs with a surgically implanted cannula to measure salivation, Pavlov Museum, (2005). Animal learning experiments are important in many aspects of psychology such as investigating the biological basis of learning, memory and behavior. In the 1890s, Ivan Pavlov famously used dogs to describe classical conditioning. The original and most famous example of a classical conditioning study. Non-human primates, cats, dogs, rats and other rodents are often used in psychological experiments. Controlled experiments involve introducing only one variable 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. Theodore Schick, (2002),

Qualitative and descriptive research

Observation in natural settings

In the same way Jane Goodall studied the role of chimpanzee social 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. Theodore Schick, (2002),

Survey questionnaires

Online 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. Keil, FC. Wilson, RA. (2001).


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, such studies can suffer from attrition due to drop-out or death of subjects. Keil, FC. Wilson, RA. (2001).

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. Keil, FC. Wilson, RA. (2001).

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 disassociations’) 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. Krstic, K. (1964).

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. Krstic, K. (1964). 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. Cohen, J. (1994).

Criticism and controversies

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. Cohen, J. (1994). 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, has 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. Cohen, J. (1994).

The concern is that this statistical method may promote trivial findings as meaningful, especially when large samples are used. Psychologists have responded with an increased use of effect size statistics, rather than sole reliance on the traditional p<.05 decision rule. Bradley Steffens (2006). 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. One argument states that some therapies are based on discredited theories and are unsupported by empirical evidence of their effectiveness. Bradley Steffens (2006).

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.


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