Introduction to the Field of Psychology

Defining Psychology

Psychology is the scientific study of human mental processes and behavior.

Learning Objectives

Identify the major branches of the field of psychology

Key Takeaways

Key Points

  • Psychology is an academic and applied discipline that seeks to understand the behavior, mental functions, and emotional processes of human beings.
  • Psychologists explore how mental and emotional factors influence individual development and behavior, and how these factors themselves can be influenced by physiological and biological processes.
  • Clinical psychologists focus on the diagnosis and treatment of mental illness; they usually work directly with clients using various forms of therapeutic treatment.
  • Research psychologists use scientific methods to explore a wide range of topics related to mental health and behavior.

Key Terms

  • psychosocial: Having both psychological and social elements.
  • cognitive: The part of mental functioning that deals with logic and memories, as opposed to affective functioning, which deals with emotions.
  • sociocultural: Of or relating to both society and culture.

Psychology is the academic and applied study of mental functions and behaviors. The word “psychology” comes from two specific Greek words—psyche, which means “soul,” “life,” or “mind,” and logia, which means “the study of.” Simply put, psychology is the study of the mind.
The overarching goal of psychology is to understand the behavior, mental functions, and emotional processes of human beings.
This field ultimately aims to benefit society, partly through its focus on better understanding of mental health and mental illness.

Most psychologists can be classified as social, behavioral, or cognitive scientists. Psychologists study many different areas, including biological foundations, mental well-being, change and development over time, the self and others, and potential dysfunctions.
They explore how psychological factors interact with biological and sociocultural factors to influence individual development. Psychologists attempt to understand not only the role of mental functions in individual and social behavior, but also the physiological and biological processes that underlie cognitive functions and behaviors.


Biology, psychology, and society shape our lives: Psychology seeks to understand how psychological factors interact with sociocultural and biological factors to influence individual development.

Psychology explores concepts such as perception, cognition, attention, emotion, phenomenology, motivation, brain functioning, personality, behavior, resilience, the unconscious mind, and interpersonal relationships. The resulting knowledge is then applied to various spheres of human activity, including the problems of individuals’ daily lives and the treatment of mental illness. Psychology has been described as a “hub science” because psychological research has links to the social sciences, natural sciences, medicine, and the humanities (such as philosophy).

Clinical vs. Non-Clinical Psychology

Clinical psychology focuses on the diagnosis and treatment of mental disorders and mental illness. Psychologists working in a clinical capacity (such as therapists or counselors) work with clients who are struggling with mental illness to assess, diagnose, and implement various forms of therapeutic treatment. Much of this treatment is based on clinical research.

While clinical psychologists tend to work directly with clients, non-clinical psychologists focus more heavily on research. Research psychologists employ scientific methods to explore relationships between various psychosocial variables and examine a wide range of topics related to mental processes and behavior. Researchers and other non-clinical psychologists often work in university psychology departments or teach in other academic settings (e.g., medical schools or hospitals). Some are employed in industrial and organizational settings, in health-care settings, in the media, in sports, or in forensic investigation and other law-related fields.

Early Roots of Psychology

The field of psychology emerged as a scientific discipline in the 19th century, but its roots go back to ancient philosophy.

Learning Objectives

Describe the philosophical roots of what would later become the field of psychology

Key Takeaways

Key Points

  • Early Greek philosophers such as Socrates, Plato, and Aristotle explored topics such as pleasure, pain, knowledge, motivation, rationality, and mental illness—topics often discussed in psychology today.
  • In the 17th century, French mathematician and philosopher René Descartes theorized that the body and mind are separate entities. This concept came to be known as dualism.
  • English philosophers Thomas Hobbes and John Locke disagreed with the concept of dualism, arguing instead that sensations, images, thoughts, and feelings are physical processes that occur within the brain.
  • Psychology became a self-conscious field of experimental study in 1879, when German scientist Wilhelm Wundt founded the first laboratory dedicated exclusively to psychological research.
  • Edward B. Titchener expanded upon Wundt’s ideas to found the theory of structuralism, which attempted to understand the mind as the sum of varying underlying parts.
  • Functionalism, founded by William James in the late 19th century, offered an alternative to structuralism by focusing largely on the functions of the mind.

Key Terms

  • dualism: In psychology, the belief that the mind and body are separate entities.
  • monism: In psychology, the belief that the mind and body are intricately connected rather than separate entities.
  • psychoneuroimmunology: The study of the interactions between behavioral, neural, endocrine, and immune functions.

Many cultures throughout history have speculated on the nature of the mind, heart, soul, spirit, and brain. Philosophical interest in behavior and the mind dates back to the ancient civilizations of Egypt, Greece, China, and India. Psychology was largely a branch of philosophy until the mid-1800s, when it developed as an independent and scientific discipline in Germany and the United States. These philosophical roots played a large role in the development of the field.

Early Philosophy

From approximately 600 to 300 BC, Greek philosophers explored a wide range of topics relating to what we now consider psychology. Socrates and his followers, Plato and Aristotle, wrote about such topics as pleasure, pain, knowledge, motivation, and rationality. They theorized about whether human traits are innate or the product of experience, which continues to be a topic of debate in psychology today. They also considered the origins of mental illness, with both Socrates and Plato focusing on psychological forces as the root of such illnesses.


Plato and Aristotle: Plato, Aristotle, and other ancient Greek philosophers examined a wide range of topics relating to what we now consider psychology.

17th Century

René Descartes, a French mathematician and philosopher from the 1600s, theorized that the body and mind are separate entities, a concept that came to be known as dualism. According to dualism, the body is a physical entity with scientifically measurable behavior, while the mind is a spiritual entity that cannot be measured because it transcends the material world. Descartes believed that the two interacted only through a tiny structure at the base of the brain called the pineal gland.

Thomas Hobbes and John Locke were English philosophers from the 17th century who disagreed with the concept of dualism. They argued that all human experiences are physical processes occurring within the brain and nervous system. Thus, their argument was that sensations, images, thoughts, and feelings are all valid subjects of study. As this view holds that the mind and body are one and the same, it later became known as monism. Today, most psychologists reject a rigid dualist position: many years of research indicate that the physical and mental aspects of human experience are deeply intertwined. The fields of psychoneuroimmunology and behavioral medicine explicitly focus on this interconnection.

Psychology as an Independent Discipline

The first use of the term “psychology” is often attributed to the German scholastic philosopher Rudolf Göckel, who published the Psychologia hoc est de hominis perfectione, anima, ortu in 1590. However, the term seems to have been used more than six decades earlier by the Croatian humanist Marko Marulić in the title of his Latin treatise, Psichiologia de ratione animae humanae. The term did not come into popular usage until the German idealist philosopher Christian Wolff used it in his Psychologia empirica and Psychologia rationalis (1732–1734). In England, the term “psychology” overtook “mental philosophy” in the middle of the 19th century.

Wilhelm Wundt

The late 19th century marked the start of psychology as a scientific enterprise. Psychology as a self-conscious field of experimental study began in 1879, when German scientist Wilhelm Wundt founded the first laboratory dedicated exclusively to psychological research in Leipzig. Often considered the father of psychology, Wundt was the first person to refer to himself as a psychologist and wrote the first textbook on psychology, entitled Principles of Physiological Psychology.

Wundt believed that the study of conscious thoughts would be the key to understanding the mind. His approach to the study of the mind was groundbreaking in that it was based on systematic and rigorous observation, laying the foundation for modern psychological experimentation. He systematically studied topics such as attention span, reaction time, vision, emotion, and time perception. Wundt’s primary method of research was ” introspection,” which involves training people to concentrate and report on their conscious experiences as they react to stimuli. This approach is still used today in modern neuroscience research; however, many scientists criticize the use of introspection for its lack of objectivity.


Wilhelm Wundt

Wilhelm Wundt is considered by many to be the founder of psychology. He laid the groundwork for what would later become the theory of structuralism.


Edward B. Titchener, an English professor and a student under Wundt, expanded upon Wundt’s ideas and used them to found the theory of structuralism. This theory attempted to understand the mind as the sum of different underlying parts, and focused on three things: (1) the individual elements of consciousness; (2) how these elements are organized into more complex experiences; and (3) how these mental phenomena correlate with physical events.

Titchener attempted to classify the structures of the mind much like the elements of nature are classified in the periodic table—which is not surprising, given that researchers were making great advancements in the field of chemistry during his time. He believed that if the basic components of the mind could be defined and categorized, then the structure of mental processes and higher thinking could be determined. Like Wundt, Titchener used introspection to try to determine the different components of consciousness; however, his method used very strict guidelines for the reporting of an introspective analysis.

Structuralism was criticized because its subject of interest—the conscious experience—was not easily studied with controlled experimentation. Its reliance on introspection, despite Titchener’s rigid guidelines, was criticized for its lack of reliability. Critics argued that self-analysis is not feasible, and that introspection could yield different results depending on the subject.


As structuralism struggled to survive the scrutiny of the scientific method, new approaches to studying the mind were sought. One important alternative was functionalism, founded by William James in the late 19th century. Built on structuralism’s concern with the anatomy of the mind, functionalism led to greater concern with the functions of the mind, and later, to behaviorism.

Functionalism considers mental life and behavior in terms of active adaptation to the person’s environment. James’s approach to psychology was less concerned with the composition of the mind and more concerned with examining the ways in which the mind adapts to changing situations and environments. In functionalism, the brain is believed to have evolved for the purpose of bettering the survival chances of its carrier by acting as an information processor: its role is essentially to execute functions similar to the way a computer does.

Psychology 101—Wundt and James: structuralism and functionalism: Here, the foundations of structuralism and functionalism are contrasted. Structuralism’s reliance on introspection eventually proved unscientific. Functionalism’s emphasis on the scientific study of the adaptive functions of behaviors and mental processes advanced the study of psychology as a science.

Current Issues and Debates in Psychology

Debates and controversies in psychology have spanned the decades and continue to change over time.

Learning Objectives

Analyze the current issues and debates taking place in modern psychology

Key Takeaways

Key Points

  • Psychologists continue to debate controversial issues in their field, many of which can be seen in the recent changes to the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5).
  • One of the ongoing debates in psychology concerns how to define the concepts of “normaland “healthy”; what is healthy for one person may not be healthy for another, and perceptions of normality are largely influenced by societal norms.
  • Psychologists often debate whether human behavior is influenced more by biological or environmental factors—a debate referred to as “nature vs. nurture.”
  • Current debates stemming from the changes to the DSM-5 include controversies around the diagnoses of autism spectrum disorder, gender dysphoria, depressive disorders, and borderline personality disorder.
  • Electroconvulsive therapy (ECT), while shown to improve symptoms of severe mental illnesses, continues to be a controversial form of treatment due to its side effects.

Key Terms

  • autism: A bio-neurological disorder that is observable in early childhood with symptoms of abnormal self-absorption, characterized by lack of response to other humans and limited ability or desire to communicate and socialize.
  • depathologizing: The act of decategorizing something as a disease or illness.
  • neurological: Dealing with the brain or the study of the brain.

Psychological debates have spanned the decades and continue to change over time. With the 2013 release of the 5th edition of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5), psychologists continue to debate controversial issues in their field.

Defining “Normal” and “Healthy”

One of the ongoing debates in psychology is how to define the concepts of “normaland “healthy.” Psychologists often rely on these terms to assess, diagnose, treat, and counsel individuals who are experiencing mental-health difficulties; however, these terms are subject to interpretation. What is normal or healthy behavior for one person may be unhealthy or ineffective for someone else. Behavior can be normal for an individual (intrapersonal normality) when it is consistent with the most common behavior for that person, even if that behavior leads to negative consequences.

“Normal” is also used to describe when someone’s behavior conforms to the most common or accepted behavior in society (known as conforming to the norm). Definitions of normality vary by person, time, place, and situation, and are overwhelmingly shaped by cultural and societal standards and norms. These standards and norms change over time, and perceptions of normality change along with them. Critics argue that perceptions of normality are inherently subject to value judgments, biases, and assumptions, and can have social ramifications. For example, someone being seen as “normal” or “not normal” can result in them being included, excluded, or stigmatized by larger society. In 2011, the British Psychological Society argued that the DSM-5 should consider mental disorders on a spectrum along with normality:

“[We recommend] a revision of the way mental distress is thought about, starting with recognition of the overwhelming evidence that it is on a spectrum with ‘normal’ experience, and that psychosocial factors such as poverty, unemployment and trauma are the most strongly-evidenced causal factors.”

Nature vs. Nurture Debate

One of the central debates in psychology involves the origin of human behavior. Is behavior caused by biological factors present in the human body (nature), or is it caused by interactions between the individual and his or her environment (nurture)?

Strict adherents of the nature philosophy often use genetic code as support for their theory. However, it is well documented that interaction with one’s environment can provoke changes in brain structure and chemistry and that situations of extreme stress can cause problems like depression. Psychologists today generally believe that human behavior is affected by a combination of both biological and environmental factors.

Changes to (and Controversies within) the DSM-5

Autism Spectrum Disorder

Many of the current debates in psychology can be seen in the recent changes to the DSM-5.
One major change is within the category of autism spectrum disorders, which no longer contains Asperger’s syndrome as a diagnosis. Rather, all children are classified under the term “autism spectrum disorder” (ASD) and given a rating or mild, moderate, or severe.

Autism is a neurological disorder that has become increasingly prevalent in recent years, affecting about 20 per 1,000 children in the United States in 2012. It is unclear whether this growth is due to changes in autism’s actual incidence or to changes in the rate of reporting. Disorders within the autism spectrum are characterized by impaired social interaction, impaired verbal and nonverbal communication, and restricted or repetitive behavior. For years, researchers have tried to find the cause of autism, and everything from vaccines to maternal depression have been cited but never proven. While the general treatment for autism is applied behavior analysis (ABA), or other behavioral therapies, many people look for alternative treatments such as diet or supplements.

Controversies surrounding the diagnosis and its treatment include the relevance of rating the severity of the disorder, and whether or not to include children with varying severity of ASD in the general-education population. Controversy also exists around the use of ABA as a treatment for ASD. In this treatment, child-specific reinforcers (e.g., stickers, praise, candy, bubbles, and extra play time) are used to reward and motivate autistic children when they demonstrate desired behaviors such as sitting on a chair when requested, verbalizing a greeting, or making eye contact. Punishments, such as a timeout or a sharp “No!” from the therapist or parent, might be used to discourage undesirable behaviors such as pinching, scratching, and pulling hair. While it has been shown to be effective in shifting the behaviors of those with ASD, some argue that the treatment serves to pathologize and further marginalize those on the spectrum by trying to “normalize” autistic behaviors.


Reports of autism are on the rise: Reports of autism cases per 1,000 children increased dramatically in the US from 1996 to 2007. It is unknown how much, if any, of this growth is due to changes in autism’s actual incidence (as opposed to changes in the rate of reporting).

Gender Dysphoria

Another recent change to the DSM-5 is the renaming of ” gender identity disorder” to “gender dysphoria.” The change separates adults, children, and adolescents appropriately by developmental stages, and was moved from the sexual disorders category to a separate category of its own. One of the major impacts of this change is the reduction of stigma by changing the language from “disorder” to “dysphoria,” which serves as a step toward depathologizing people who identify as transgender or differently gendered. At the same time, transgender people seeking surgical or hormonal treatment have historically been forced to rely on the diagnosis of gender identity disorder in order to access the appropriate treatment, however stigmatizing the diagnosis may be. It is unclear what effect this change in language will have on individuals’ ability to access appropriate medical care.

Depressive Disorders

Within the depressive disorders of the DSM-5, bereavement exclusion no longer exists; this means that people who are in severe depressive states due to grief can be diagnosed with clinical depression. Under the new guidelines, certain responses to grief could be labeled as pathological disorders, instead of being recognized as normal human experiences

Borderline Personality Disorder

In 2003, the Treatment and Research Advancements Association for Personality Disorders (TARA APD) campaigned to change the name and designation of borderline personality disorder (BPD), arguing that BPD as it currently stands is “confusing, imparts no relevant or descriptive information, and reinforces existing stigma.” Instead, it proposed the name “emotional regulation disorder” or “emotional dysregulation disorder.” There was also discussion about changing borderline personality disorder, an Axis II diagnosis (personality disorders and mental retardation), to an Axis I diagnosis (clinical disorders). However, the name, the diagnostic criteria, and the description of BPD remain largely unchanged from the previous DSM-IV-TR.

Electroconvulsive Therapy

Electroconvulsive therapy (ECT) is a controversial approach to the treatment of severe mental illness that involves inducing minor seizures within the brain through electrical impulses. Much of the treatment’s controversy stems from its early usage in the 1940s, and popular-culture references, such as the film One Flew Over the Cuckoo’s Nest. ECT has been dramatically improved over time and is generally used as a treatment of last resort for severe disorders—such as major depression, schizophrenia, or bipolar mania—that do not respond to other forms of treatment. About 70 percent of patients are women. Controversy continues to surround ECT due to its side effects on memory and general cognition after treatment, as well as its debated level of effectiveness. While some studies have shown ECT to drastically improve symptoms with perhaps fewer side effects than some medications, other studies point to high rates of relapse. It is unknown why the treatment is effective in many cases of severe mental disorders.