Evolution of Psychological Science

The Evolution of Psychological Science

Psychology's Philosophical Roots

  • Psychology Defined:

    • The scientific study of mind and behavior.
    • Mind: Private events inside a person (thoughts, feelings).
    • Behavior: Public events observable by others (actions, speech).

  • Philosophical Influences:

    • Philosophers were the first to contemplate the human mind and behavior.
    • Three key ideas from philosophy are crucial to understanding modern psychology: dualism vs. materialism, realism vs. idealism, and empiricism vs. nativism.

  • Dualism vs. Materialism:

    • Dualism: Mind and body are fundamentally distinct (René Descartes).
      • Body: Material substance.
      • Mind: Immaterial substance.
      • Humans are physical containers for a nonphysical thing, "the ghost in the machine" (Gilbert Ryle).
      • Interaction problem: How does the immaterial mind interact with the material body?
    • Materialism: The mind is what the brain does (Thomas Hobbes).
      • Mental phenomena are reducible to physical phenomena.
      • Analogy: The picture is what the screen does; they don’t meet in some third place.

  • The Dualism vs. Materialism Debate:

    • Cannot be settled by facts alone.
    • Most people generally believe in something beyond the physical universe. Religions often embrace a nonphysical soul.
    • Psychologists largely lean towards materialism.
    • Psychology's goal is to explain mental phenomena in terms of physical processes in the brain.

  • Realism vs. Idealism:

    • Philosophical Realism: Perceptions are produced entirely by information from sensory organs (John Locke).
      • The eye is like a camera, producing accurate depictions of the world.
      • Example: Light bounces off a book, enters the eye, and the brain uses this information to produce an accurate perception of the book.
    • Philosophical Idealism: Perceptions are the brain’s interpretation of sensory information (Immanuel Kant).
      • Perceptions are like paintings, influenced by prior knowledge and expectations.
      • Example: The brain uses prior knowledge about books (materials, size, etc.) to interpret visual input when seeing a book.

  • The Realism vs. Idealism Debate:

    • Modern psychology supports idealism.
    • Perception is an inference, the brain’s best guess about what is out there.
    • Brains produce realistic paintings so fast we don’t generally realize we're guessing at all.

  • Empiricism vs. Nativism:

    • Philosophical Empiricism: All knowledge is acquired through experience (John Locke).
      • Newborn baby is a tabula rasa or “blank slate.”
      • Knowledge comes from observation and interaction with the world.
      • Example: Knowledge about books comes from seeing and interacting with them.
    • Philosophical Nativism: Some knowledge is innate rather than acquired (Immanuel Kant).
      • Humans are born with basic knowledge that allows them to acquire additional knowledge.
      • Example: Understanding causation is necessary to learn what happens when a book is pushed off a table.
      • Innate concepts: space, time, causality, number.

  • The Empiricism vs. Nativism Debate:

    • Modern psychology leans towards nativism.
    • Some knowledge is hardwired into our brains.
    • Even newborns have basic knowledge of physics and math.
    • The tabula is not rasa, raising questions about what is pre-programmed at birth and how experience interacts with it.
    • This discussion leads to “nature-versus-nurture” questions.

The Late 1800s: Toward a Science of the Mind

  • Psychology's Emergence:

    • Psychology has philosophical roots that date back thousands of years, but as an independent science it only started around 150 years ago when German scientists began applying the methods of physical and natural sciences to the study of the human mind.
    • Hermann Ebbinghaus: “Psychology has a long past but a short history.”

  • Structuralism: What Is the Mind Like?

    • Pioneering work in Germany.
    • Hermann von Helmholtz:
      • Physician and physicist.
      • Studied the mathematics of vision.
      • Measured reaction time to stimuli on different parts of the leg.
      • Calculated the speed of nerve impulse transmission.
    • Wilhelm Wundt:
      • Research assistant to Helmholtz, considered the "founder" of psychology, in a way.
      • Taught the first course in scientific psychology.
      • Published the first psychology textbook in 1874.
      • Opened the first psychology laboratory in Leipzig in 1879.
      • Goal: Understand the facts of consciousness and its relations.
      • Approach: Breaking down the mind into basic elements, like natural scientists break down the physical world.
      • Approach later came to be known as structuralism. What is the mind like?

  • Introspection:

    • Edward Titchener (student of Wundt) pioneered introspection.
    • Analysis of subjective experience by trained observers.
    • Observers reported on contents of their moment-to-moment experience in response to stimuli.
    • Goal: Discover the basic building blocks of subjective experience.
    • Example: Wundt identified three basic dimensions of sensation: pleasure/pain, strain/relaxation, and excitation/quiescence.

  • Decline of Structuralism:

    • Success of natural scientists in breaking down the natural world into parts.
    • Structuralism's Problem: Lack of agreement on basic elements. Introspection was subjective and varied across individuals.
    • Problem with the method: Each person's inner experience was a private event.
    • There was no way to tell if a person’s description of their experience was accurate.

  • Functionalism: What Is the Mind For?

    • William James:
      • Rejected structuralism.
      • Stream of consciousness metaphor.
      • Focus: What the mind does.
    • Functionalism: Emphasized the adaptive significance of mental processes.
    • Influence of Charles Darwin:
      • On the Origin of Species (1859).
      • Principle of natural selection.
      • Adaptive attributes become more prevalent over time.

  • Natural Selection:

    • Animals pass on physical attributes to offspring.
    • Adaptive attributes promote survival and reproduction.
    • These adaptive attributes become more prevalent over generations.
    • James reasoned that the same should be true of psychological characteristics including the mind.

  • Functionalism and the Mind

    • Consciousness evolved for a purpose.
    • Psychologists should figure out what that purpose was.
    • Functionalism got its mind from Darwin.

The Early 1900s: Psychoanalysis and Behaviorism

  • Shifting Focus

    • Structuralism and functionalism impacted few beyond academia.
    • The 20th century: Significant changes driven by figures like Freud and Watson.
      • 1 rested neurologist from Vienna. Sigmund Freud.
      • 1 failed writer from Pennsylvania: John Watson.

  • Psychoanalysis: The Mind Does Not Know Itself

    • Focus:
      • Physicians seeking to treat mental illness.
      • French physicians Jean-Martin Charcot and Pierre Janet.
      • Interested in patients exhibiting hysteria, a loss of function without physical origin.
      • Symptoms disappeared under hypnosis.
    • Sigmund Freud:
      • Viennese physician.
      • Studied with Charcot.
      • Treated patients with hysteria and nervous disorders.

  • Unconscious Mind

    • Freud believed painful childhood experiences were repressed/hidden in the unconscious mind.
    • Unconscious: The part of the mind outside awareness.
    • These repressed memories caused hysterical symptoms.
    • Psychoanalytic theory emphasized the influence of the unconscious on feelings, thoughts, and behaviors.
    • Freud regarded conscious thoughts and feelings as just the tip of the iceberg.

  • Psychoanalysis

    • The only way to confront these thoughts was through psychoanalysis.
    • A therapy that aims to give people insight into the contents of their unconscious minds.
    • Therapeutic Approach:
      • Patients lay on a couch; Freud sat behind them.
      • Dream analysis.
      • Free association.

  • Impact and Influence

    • Freuds theories had some impact on the clinicians and astonishing impact on others.
    • Experimental psychologists largely dismissed Freud (e.g., William James). Considered it nonsense.
    • Clinicians embraced psychoanalysis.
    • Freud influenced history, philosophy, literature, and art (ranked 44th most influential person in history).

  • Behaviorism: The Mind Does Not Matter

    • Response to Freud and earlier psychology.
    • John Broadus Watson:
      • Studied rat behavior.
      • Argued psychology should focus on observable behavior.
      • Rejected introspection and the study of the mind.
      • The mind was idiosyncratic, undefinable, and unmeasurable.

  • Pavlov and Watson

    • Pavlov studied digestion in dogs.
    • Dogs naturally start salivating when they are presented with food.
    • Ivan Pavlov:
      • Studied stimulus and response in dogs.
      • Dogs salivated at the sound of footsteps (associated footsteps with food).
      • Pavlov called the tone a stimulus and the salivation a response.
    • Watson argued psychology should study the relationship between stimuli and responses.
      • Psychology from the Standpoint of a Behaviorist: no discussion of consciousness, sensation, attention etc.

  • The Rise of Behaviorism

    • Watson's arguments were persuasive.
    • By 1930s, experimental psychology was behaviorism.
    • Structuralism/functionalism became historical curiosities.
    • Behaviorism as the one proper way to study human behavior.
    • John B. Watson was the founder of behaviorism.

  • Skinner

    • Burrhus Frederick Skinner:
      • Built on Watson's behaviorism.
      • Studied the effects of reward.
      • American psychologist that went to Harvard.
    • The Skinner Box:
      • Cage with a lever.
      • Pressing the lever released food.
      • Cumulative recorder tracked lever presses in real time.
      • Skinner discovered something remarkable.

  • Principle of Reinforcement

    • Animals learn to operate on their environments to produce food.
    • When the rat's behavior produced food the rat would repeat the behavior.
    • The behavior that is rewarded will be repeated, and any behavior that isn't won't.
    • Behaviro can explain the most complex human behaviors, and he made it the centerpiece of his theorizing.

  • Skinner was influential.

    • By the 1940s, the majority of experimental psychologists had been converted to Skinner’s “radical behaviorism” and were busy studying how an animal’s behavior was shaped by the consequences it produced.
    • Behaviorism was viewed as the one right way to do psychological science.

  • Extending Behaviorism

    • Skinner extended his influence by writing two controversial best-sellers —Walden II (1948) and Beyond Freedom and Dignity (1971)—in which he laid out his vision for a utopian society in which all human behavior was controlled by the judicious application of the principle of reinforcement.
    • Influence on education, government, therapies, child-rearing.
    • He claimed free will was an illusion.

The Early 1900s: Resistance to Behaviorism

  • Resistance to Behaviorism

    • Behaviorism dominated early 20th century, but not all psychologists agreed.
    • Pockets of resistance emerged, challenging behaviorist principles.

  • Gestalt Psychology

    • Max Wertheimer:
      • German psychologist interested in perception.
      • Experiment with flashing lights: Participants perceived motion when lights flashed in sequence at certain intervals.
      • The mind has theories about how the world works, and uses them to make sense of incoming sensory data
      • Wertheimer argued that physical stimuli are part of the perceptual experience, but the whole is more than the sum of its parts. Example: news ticker.
      • Gestalt psychology emphasized the way the mind creates this perceptual experience.
      • Wertheimer moved to New York in 1933 because he was Jewish.

  • Developmental Psychology

    • Sir Frederic Bartlett:
      • British psychologist.
      • Studied memory.
      • Participants read stories, then recalled them after varying time intervals.
      • Memory is not a simple recording device; minds construct memories based on expectations.
    • Bartlett helped solve a naval mystery.

  • Child Development

    • Jean Piaget:
      • Swiss psychologist studied children’s minds.
      • Examined errors children made to understand their thinking.
      • Children possess different theories of how the world works than adults.
      • Helped create developmental psychology.

  • The Rise of Social Psychology

    • Kurt Lewin:
      • Fled Europe due to Hitler in the 1930s.
      • Gestalt psychologist interested in social phenomena.
      • Behavior is a function of the person’s subjective construal of the environment.
      • Responses depend on how people think about stimuli.
      • Research on leadership, communication, attitude change, prejudice.
      • His research and theorizing gave birth to a new area of experimental psychology called social psychology.

  • Concepts central to Social Psychology

    • Solomon Asch:
      • Investigated impression formation.
      • Described a person with both positive and negative traits; order of traits influenced perception.
      • Early information shapes interpretation of later information.
      • First impressions matter.
    • Other social psychologists: Carl Hovland, Irving Janis, Gordon Allport, Muzafer Sherif, Fritz Heider.
    • Concepts: Beliefs, stereotypes, identities, and intentions, all mental processes are banished from behaviorism.

The Late 1900s: The Cognitive Revolution

  • Chomsky's Critique of Skinner

    • Began passive resistance.
    • B.F. Skinner's Book
    • Skinner (1957) published Verbal Behavior, a behaviorist account of language acquisition.
    • Linguist Noam Chomsky Critiqued
    • 1959: Chomsky published a 33-page critique, arguing behaviorism couldn’t explain language-learning.
    • Children create sentences they’ve never heard before. Grammar is complex and innate.

  • Out with the old!
    *What's the new!

  • Cognitive Psychology

    • A mindless soul less machine.
    • ENIAC built in 1945
    • By the 1960s computer became smaller and more available.
    • Scientists and Mathematicians wondered whether they could ever be made to think.
    • How to talk with the mind respectably again.

  • A new way to think

    • Marlyn Wescoff (left) and Ruth Lichterman (right) are programming ENIAC
    • Present the computer with a stimulus (“2 + 2 = ?”). Give it a program a set of instructions

The Early 2000s: New Frontiers

  • Continued Evolution of Psychology

    • Since the 2000s, psychology has made new strides and exciting areas have emerged.
    • Looking “down a level” to biology to understand the neural basis of metal life. Neuroscience.
    • Looking “up a level” to sociology and anthropology, to understand its cultural origins.

  • Neuroscience

    • The mind what the brain does
    • Historically, knowledge of the brain came from studying damaged brains.

  • Cultural Psychology

    • Cultural differences in countries/towns.
    • More alike in human beings but more different.
    • Culture refers to the values, traditions, and beliefs.
    • Other dimensions on which people differ.

  • Cultural psychology is the study of

    • How culture influences mental life.

Becoming a Psychologist

  • Common Misconceptions

    • If you tell someone you’re a psychologist, they typically (a) run away or (b) ask if you are analyzing them, and then run away.
      Psychologists can look directly into their minds and read their thoughts, especially the sexual ones.

  • American Psychological Association (APA)

    • Founded in 1892 by William James and six other psychologists.
    • Represents psychology as a profession.
    • Today has more than 75,000 members.

  • Gender and Diversity

    • In 1988, a second professional organization formed, and that this Association for Psychological Science would soon expand to 30,000 members.
    • In 2017, about 70% of PhDs in psychology were women which is different from the past.

  • Overcoming Historical Barriers

    • Mary Whiton Calkins:
      • Studied at Harvard with James, but was denied a PhD due to being a woman.
      • Became the first female president of APA.
    • Margaret Floy Washburn:
      • First woman to receive a PhD in psychology.
      • Served as APA president.
    • Today, women earn the majority of PhDs in psychology from American universities.

  • People of Color

    • Founding meeting in 1892.
    • Francis Cecil Sumner (1895–1954) became the first African American to receive a PhD in psychology, and in 1970, his student Kenneth Clark (1914–2005) became the first African American to serve as APA’s president.
    • America has changed and so has psychology that has made the seven founders proud.

  • What’s the level of training to be a psychologist?

    • College students with psychology degree have a bachelor's degree, but cannot call themselves psychologist.
    • It requires an additional advanced degree. Ph. D. is the most common.
    • The Ph. D. requires you to attend graduate school where you need to do original research.

  • What does a psychologist do for work?

    • Professorship at a college or university
    • They can offer the service assessment and treating people with psychological problems as therapist with a practice.
    • Different degrees come with different privileges
    • People with MD can prescribe medications but those with a Ph. D. cannot

  • Specific Jobs

    • School psychologists ( offer guidance to the student)
    • Industrial and organizational psychology business employees
    • Sports psychologists
    • and so on