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Psychology

<OpenstaxParagraph>
	Perhaps the simplest approach to conceptualizing psychological disorders is to label behaviors, thoughts, and inner experiences that are atypical, distressful, dysfunctional, and sometimes even dangerous, as signs of a disorder. For example, if you ask a classmate for a date and you are rejected, you probably would feel a little dejected. Such feelings would be normal. If you felt extremely depressed—so much so that you lost interest in activities, had difficulty eating or sleeping, felt utterly worthless, and contemplated suicide—your feelings would be <OpenstaxTerm>atypical</OpenstaxTerm>, would deviate from the norm, and could signify the presence of a psychological disorder. Just because something is atypical, however, does not necessarily mean it is disordered.
</OpenstaxParagraph>
<OpenstaxParagraph>
	For example, only about 4% of people in the United States have red hair, so red hair is considered an atypical characteristic (<a href="#Figure_15_01_Red_Hair">Figure 15.2</a>), but it is not considered disordered, it’s just unusual. And it is less unusual in Scotland, where approximately 13% of the population has red hair (“DNA Project Aims,” 2012). As you will learn, some disorders, although not exactly typical, are far from atypical, and the rates in which they appear in the population are surprisingly high.
</OpenstaxParagraph>
<OpenstaxFigure id="Figure_15_01_Red_Hair" src="https://openstax.org/apps/archive/20240226.174525/resources/35b14c98b57c974c825962d51107a642bd10854e" alt="Photograph A shows Isla Fischer. Photograph B shows Prince Harry. Photograph C shows Marcia Cross." mediaType="image/jpeg" width="731" height="293" />
<OpenstaxFigureText width="731">
	<strong>Figure 15.2</strong> Red hair is considered unusual, but not abnormal. (a) Isla Fischer, (b) Prince Harry, and (c) Marcia Cross are three natural redheads. (credit a: modification of work by Richard Goldschmidt; credit b: modification of work by Glyn Lowe; credit c: modification of work by Kirk Weaver)
</OpenstaxFigureText>
<OpenstaxParagraph>
	If we can agree that merely being atypical is an insufficient criterion for a having a psychological disorder, is it reasonable to consider behavior or inner experiences that differ from widely expected cultural values or expectations as disordered? Using this criterion, a person who walks around a subway platform wearing a heavy winter coat in July while screaming obscenities at strangers may be considered as exhibiting symptoms of a psychological disorder. Their actions and clothes violate socially accepted rules governing appropriate dress and behavior; these characteristics are atypical.
</OpenstaxParagraph>

15.1.1 Definition of a Psychological Disorder

1 Introduction to Psychology

1.1 What Is Psychology?

1.1.1 Why Study Psychology?

1.2 History of Psychology

1.2.1 Wundt and Structuralism

1.2.2 Functionalism

1.2.3 Freud and Psychoanalytic Theory

1.2.4 Wertheimer, Koffka, Köhler, and Gestalt Psychology

1.2.5 Pavlov, Watson, Skinner, and Behaviorism

1.2.6 Maslow, Rogers, and Humanism

1.2.7 The Cognitive Revolution

1.2.8 Multicultural And Cross-Cultural Psychology

1.2.9 Women in Psychology

1.3 Contemporary Psychology

1.3.1 Biopsychology and Evolutionary Psychology

1.3.2 Sensation and Perception

1.3.3 Cognitive Psychology

1.3.4 Developmental Psychology

1.3.5 Personality Psychology

1.3.6 Social Psychology

1.3.7 Industrial-Organizational Psychology

1.3.8 Health Psychology

1.3.9 Sport and Exercise Psychology

1.3.10 Clinical Psychology

1.3.11 Forensic Psychology

1.4 Careers in Psychology

1.4.1 Other Careers in Academic Settings

1.4.2 Career Options Outside of Academic Settings

2 Psychological Research

2.1 Why Is Research Important?

2.1.1 Use of Research Information

2.1.2 NOTABLE RESEARCHERS

2.1.3 The Process of Scientific Research

2.2 Approaches to Research

2.2.1 Clinical or Case Studies

2.2.2 Naturalistic Observation

2.2.3 Surveys

2.2.4 Archival Research

2.2.5 Longitudinal and Cross-Sectional Research

2.3 Analyzing Findings

2.3.1 Correlational Research

2.3.2 Causality: Conducting Experiments and Using the Data

2.3.3 Reliability and Validity

2.4 Ethics

2.4.1 Research Involving Human Participants

2.4.2 Research Involving Animal Subjects

3 Biopsychology

3.1 Human Genetics

3.1.1 Genetic Variation

3.1.2 Gene-Environment Interactions

3.2 Cells of the Nervous System

3.2.1 Neuron Structure

3.2.2 Neuronal Communication

3.2.3 Neurotransmitters and Drugs

3.3 Parts of the Nervous System

3.3.1 Peripheral Nervous System

3.4 The Brain and Spinal Cord

3.4.1 The Spinal Cord

3.4.2 The Two Hemispheres

3.4.3 Forebrain Structures

3.4.4 Midbrain and Hindbrain Structures

3.4.5 Brain Imaging

3.5 The Endocrine System

3.5.1 Major Glands

4 States of Consciousness

4.1 What Is Consciousness?

4.1.1 Biological Rhythms

4.1.2 Problems With Circadian Rhythms

4.2 Sleep and Why We Sleep

4.2.1 What is Sleep?

4.2.2 Why Do We Sleep?

4.3 Stages of Sleep

4.3.1 NREM Stages of Sleep

4.3.2 REM Sleep

4.4 Sleep Problems and Disorders

4.4.1 Insomnia

4.4.2 Parasomnias

4.4.3 Sleep Apnea

4.4.4 Narcolepsy

4.5 Substance Use and Abuse

4.5.1 Substance Use Disorders

4.5.2 Drug Categories

4.6 Other States of Consciousness

4.6.1 Hypnosis

4.6.2 Meditation

5 Sensation and Perception

5.1 Sensation versus Perception

5.1.1 Sensation

5.1.2 Perception

5.2 Waves and Wavelengths

5.2.1 Amplitude and Wavelength

5.2.2 Light Waves

5.2.3 Sound Waves

5.3 Vision

5.3.1 Anatomy of the Visual System

5.3.2 Color and Depth Perception

5.4 Hearing

5.4.1 Anatomy of the Auditory System

5.4.2 Pitch Perception