Week 1

• Freud and Modern Psychology

  • Freud’s methods are unrepresentative of contemporary psychological research.
  • Modern psychology relies heavily on controlled experimentation, which Freud did not use.
  • Freud's reliance on case studies and introspection does not meet modern scientific standards.
  • His theories are not supported by a substantial, replicable database
  • His focus on theoretical structures lacked the empirical foundation typical of modern psychology.
• Diversity of Modern Psychology

  • Modern psychology encompasses a wide range of content and perspectives, reducing its coherence as a unified discipline.
  • Described by Henry Gleitman as a “loosely federated intellectual empire” spanning biological to social sciences.
  • Criticized by some, like Clifford Geertz, as an assortment of disconnected inquiries rather than a unified field.
  • Psychology lacks a single, grand unifying theory, which disappoints some students and fuels criticisms of the field.
• Diversity of Modern Psychology (2)

  • Theoretical unification is challenging
  • Evolutionary psychology and social cognitive neuroscience aim to unify aspects of the field.
  • Some researchers view psychology's diversity as a strength, citing its wide-reaching implications for other sciences.
  • Cacioppo (2007a) identifies psychology as a “hub discipline” that influences many scientific fields.
  • Physics, chemistry, and medicine also lack unifying theories and have fragmented into specialties, so this fragmentation is not unique to psychology and does not undermine its scientific validity.
• Unity in Science


  • Many fields (e.g., sociology, economics, anthropology) also study human behavior, making psychology’s subject matter non-unique.
  • Applied goals like helping people or counseling are shared with professions such as social work, education, and nursing.
• How is Psychology distingued?

  • Studying human and nonhuman behavior using scientific methods.
  • Deriving practical applications based on scientific evidence
  • Psychology must adhere to scientific principles to maintain its relevance and distinction.
  • If it abandons scientific rigor, it risks becoming redundant, as its concerns could devolve to other disciplines.
• What is science, and what is it not defined by

  • Science is a systematic method of observing and reasoning about the universe to deeply understand its workings.
  • subject matter: Any topic, including human behavior, can be studied scientifically.
  • tools or equipment: Test tubes, computers, and white coats are tools but do not determine whether something is scientific.
• Features of a Science

  Systematic Empiricism:

  • Empiricism = relying on observation to gain knowledge.
  • Observations must be systematic (structured and theory-driven) to uncover meaningful insights, not just random facts.
  • Production of Public Knowledge:
  • Science requires sharing knowledge openly for validation and replication (explored in more detail later).
  • Examination of Solvable Problems:
  • Science focuses on questions that can be addressed through empirical evidence and logical reasoning.
• Structural observation


  • Scientific observations aim to test theories and differentiate between competing explanations.
  • Unstructured observations, while informative, do not lead to scientific understanding.
• History of empiricism


  knowledge was often sought through pure thought or authority, not observation.
• Public science


  • Scientific knowledge becomes valid only when shared with the scientific community for replication, criticism, and testing.
  • Private or unverified claims cannot be considered scientific.
• Replicable science


  • replication ensures findings are reliable and not the result of individual error or bias.
  • Replicated findings become public property, allowing others to extend, challenge, or apply them.
• Peer review


  • experts critiquing a submitted study before publication, ensuring it meets minimum scientific standards.
  • While not perfect, peer review helps maintain quality and objectivity in scientific literature.
  • Peer review acts as a consumer protection mechanism against pseudoscientific claims.
  • Ignoring this process risks falling prey to the influence of profit-driven pseudoscience industries.
• Pseudoscience vs Science


  • Pseudoscience often bypasses peer review and relies on media campaigns to promote claims.
  • Valid scientific findings are published in peer-reviewed journals, making this a crucial criterion for evaluating legitimacy.
• What makes something falsifiable?

  • Theories are useful when their predictions are specific enough to be tested (not vague and generic).
  • These predictions specify what should (and therefore should not) happen.
  • If the outcome is unexpected, then the theory is falsified. The theory can then be modified or scrapped.
  • Theories that do not generate prediction, or those which cannot rule out possible observations cannot drive progress.
• Falsifiable


  A fundamental principle underlying all scientific hypotheses/theories. According to Popper (1902 – 1994), a theory is falsifiable if it meets the following conditions:

  • (1) makes a specific prediction
  • (2) this prediction is observable/testable. A theory is falsifiable only when an experiment/observation could conceivably disprove the theory.
• Falsified


  The condition of falsification has been observed.

  A hypothesis or theory demonstrated to be false (i.e., untrue) by contradictory empirical data collected via systematic observation/experimentation.
• False

  A theory shown to be untrue by observation or experimentation.
• Sequence of empirical testing

  theory -> prediction -> test -> theory modification
• Hostility towards psychology


  • deny that it is a science, and that it can estabish empirical facts about human behaviour
  • Threatens their religious beliefs
  • very new and young science
• Falsifiability criterion


  Scientific theories must always be stated in a way that the predictions derived from them could potentially be shown to be false

  • the prediction must be specific
  • imply what should happen, but also what will not happen
  • if those do happen, then the theory is wrong
• Theory


  Interrelated set of concepts used to explain a body of data to make predictions about results of future experiments
• Hypotheses


  Specific predicitons derived from theories
• Confirmation and Falsifiability


  Not quantity, but quality of confirming instances

  Use falsifiability criterion to evaluate evidence.
• Essentialism


  The idea that only good scientific theories are those that give ultimate explanations of phenomena in terms of their underlying essences/essential properties
• Why do scientisits not answer essentialist questions?

  • claim that questions about ultimates are unaswereable
  • science do not claim to produce perfect knowledge
  • science is not an error-free process, but elimiates errors part of our knowledge base
  • choke off inquiry
  • a free and open pursuit of knowledge is a prerequisite for scientific activity
• Difference between essentialism and science

  The MEANING of a concept in science is determined after extensive investigation of the phenomena the term relates to, not before, using data, not debates

  The key to progress in science is to abandon essentialism and adopt operationalism
• Operationism


  The idea that concepts in scientific theories must be linked to observable events that can be measured, removing emotions
• What makes operational definition of a concept useful?

  Reliability

  Validity
• Reliability


  consistency of a measuring instrument, arriving at the same measurement if you assess the same concept multiple times
• Construct Validity


  whether a measuring instrument is measuring what it is supposed to measure
• Pre-existing bias problem


  We study psychology with intuitive theories of personality and human behaviour because we have been explaining behaviour to ourselves all our lives
• Hostility against operationalism 


  • Dehumanises people, instead base views of human beings on intuition
  • seek essentialist answers to human problems instead
• Parsimony


  When two theories have the same explanatory power, the simpler theory (with fewer concepts) is preferred

  • more falsifiable in future tests
• Theory


  A hypothesised general principle that explains known findings about a topic and from which new hypotheses can be generated
• Levels of measurement (Categorical)

  Binary variable: only two categories (dead or alive)

  Nominal variable: more than two categories (omnivore, vegetarian, carnivore)

  Ordinal variable: categories in a logical order (fail, pass, merit, distinction)
• Levels of measurement (Continuous)

  • Interval variable: equal differences on the variable (equal differences on property being measured) (6, 8, 10, 12)
  • Ratio variable: same as interval, but ratios of scores on scale must also make sense (someone scoring 16 on anxiety scale, is twice as anxious as someone scoring 8)
• Measurement error 


  Discrepancy between the actual value we want to measure, and the number we use to represent the value

  • you weight 80 kg
  • scale scale says 83kg
  • measurement error = 3kg
• Content validity


  Evidence that the content of a test corresponds to the content

  • if a math test is meant to evaluate algebra skills, it should include questions on all key algebra topics—not geometry or unrelated math areas.
• Ecological validity


  Results of a study, test or experiment can be applied and allow inferences to the the real world
• Test-retest reliability 


  Ability of a measure to produce consistent results when the same entities are measured at two different times