Unit 1 - The Scientific Foundations of Psychology

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Summary
● In this unit, you will be studying how psychology went from abstract to concrete
knowledge. Research methods, statistics, and ethics will be discussed.

History
● Psychology mixes physiology (physical studies) and philosophy
● It started with the early philosophers Socrates, Aristotle, and Plato
○ They debated upon nature vs. nurture and where the actual “mind” was
● John Locke - started the idea of Tabula Rosa, where the mind is like a blank slate at
birth, and any healthy baby can become anything

Important People
(Wave 1)
● William James- in 1890, he wrote the first textbook about psychology and began
functionalism (analyzing the purpose of behavior)
● William Wundt- set up the first lab to study psychology in Germany and began
structuralism (used introspection, looking inside oneself to examine mental experience,
and certain structures made the mind)
(Wave 2)
● Gestalt- (Wertheimer) criticized James and Wundt for not considering the “whole self”
(Wave 3)
● Freud- psychoanalysis (conscious and unconscious processes)
(Wave 4)
● Skinner- behaviorism (changing behaviors can be treatment, conditioning can be used)
(Wave 5) Current Wave
● Eclectic approach- there are multiple perspectives
Research Methods (Lots of Vocabulary!)
● Theory: based on facts/evidence

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● Hypothesis: testable prediction to a theory
○ Ex: If kids eat more sugar, they will be more distracted, impulsive, etc.
● Null Hypothesis: try disproving our own ideas; is there a statistically significant
difference (5% difference or more between having the treatment or not)
○ Ex: “Plant growth is not affected by light color.”
● Hindsight bias: Upon hearing research findings (or other results), people have the
tendency to believe that they could have figured it out.
○ Ex: Saying “I knew it all along” at an end of a sports game.
● Operational definition: Explaining how you will measure a variable so that replication
of an experiment is made easier.
○ Ex: If a psychologist is doing an experiment where they are seeing how anxiety
varies between age groups, they can operationally define anxiety as the rating
participants choose on a survey.
● Coincidence Error: Humans have tendency to look for patterns so we might see patterns
in random things
● Overconfidence Error: Sometimes, we are sure we are right, and that causes error.
● Sampling: process by which participants/subjects are chosen for participating in a study
● Representative Sample: This is the goal of sampling; the sample is able to represent a
larger population effectively.
○ Ex: Choosing people of various groups is more representative of a city than, for
example, a sample of only old men in the city.

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 ● Random Selection: This increases the likelihood of a sample being representative.
○ Ex: When trying to get a sample of 100 out of 900 high schoolers in a certain
school, you can choose the students based on their ID numbers. This allows you
to get people of random grade, age, and gender.
● Stratified Sample: Allows researchers to ensure that a sample is directly representative
through a certain criteria.
○ Ex: Pretend the study should be representative of race for the best results. If the
population of 1000 has 500 white, 300 black, and 200 Latino people, then for a
sample of 100, there would be 50 white, 30 black, and 20 Latino people.

Experimental Method
● In an experiment, one can use the experimental method. This is preferred for an
experiment since it is able to show a cause and effect result through manipulating a
variable. The disadvantage is that what happens in a controlled setting may not be
generalizable to the real world.
○ Confounding variable: Any difference between the experimental and control
conditions that might affect the dependent variable of an experiment. (These
should be eliminated because they mess with the validity of the experiment.)
■ If you are testing to see how the amount of sleep affects performance, the
results may be influenced by foods that each person eats.
○ An experiment should utilise random assignment to figure out who goes into the
control group, the group receiving no treatment, and who goes into the
experimental group, the group receiving treatment.
■ This gets rid of bias, which is a major issue in experiments.
● The independent variable is whatever the experimenter is manipulating
○ Ex: If you are testing to see how amount of sleep affects performance, the hours
of sleep is the independent variable because that is affecting performance and you
are changing that.

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● The dependent variable is the variable which is measured
○ Ex: If you are testing to see how amount of sleep affects performance, the
performance level is the dependent variable since that is what the experimenter is
figuring out.
● Experimental bias is the unconscious tendency for researchers to treat members of the
experimental or control group differently because he/she knows what the experiment is
about.
○ Ex: A researcher who hates people who use drugs might treat the group who uses
drugs differently than the group which doesn’t use drugs (unconsciously)
● Subject bias, where the subjects of the experiment act differently because they know
what experimenters want; can be eliminated through a single-blind procedure in which
the subjects don’t know what is being tested.
○ The Hawthorne Effect was discovered through a study in which workers were
monitored to see if the amount of light in the room affected productivity. This
effect was shown when all the workers just worked harder because they were
being watched. This is why a control group is used to prevent this.
● In order to fix the problem of experimental bias, researchers may utilize the double-blind
procedure in which both the subjects and researchers are unaware of the control vs.
experimental group. This makes placebos more effective.
○ The Placebo Effect controls for possible subject bias where the subjects’
knowledge of the treatment may cause them to think they are having the effects.
■ Ex: The control group gets a placebo and the experimental group gets the
actual treatment. When studying the effectiveness of a pill, the
experimental group would get the actual pill, and the control group would
get something like a sugar pill.

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Correlational Studies
● Correlation: Expresses a relationship between two variables. It can be positive, negative,
strong, or weak.
○ Positive correlation is when both variables increase
○ Negative correlation is when one variable increases and the other decreases
● CORRELATION DOES NOT MEAN CAUSATION!
● Scatterplots: Used to plot negative/positive correlation. A perfect positive or perfect
negative graph would be a linear graph.
● Correlation Coefficient: On a scale from -1 to +1. -1 and +1 are both the strongest
correlations (one strongly negative and one strongly positive).

Other Kinds of Studies

● Naturalistic observation: Research conducted in a natural habitat
○ Ex: Monkeys in the wild, children in the park rather than lab
● Case Study: In-depth detailed study of an individual or small groups. The problem with
this is that it is not generalizable.
○ Ex: Studying Derek Paravicini, who is blind and autistic, but is a brilliant pianist
● Surveys/Interviews: having people report their own attitudes/behaviors. It is not super
accurate, but you can reach a larger audience.
○ Random sampling must be done in order for surveys to get the best results.

Measures of Central Tendency

● Mode: the most common number, score, etc.
● Mean: add all the data, and divide by how many there are to find the average
● Median: the number in the middle when listed out; center value in data

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Measures of Variation
● Range: the difference between the largest and smallest number
● Standard Deviation: how far a value is from the mean

Les
Mor

● Intelligence test distribution is a normal curve

● Income distribution is skewed

Ethics in Psychology
● Milgram’s Obedience Test: Participants were told to give electric shocks to a person
(they weren’t actually, though, but they had no idea); researchers were seeing how much
they would do if an “official” person told them to.
○ This was unethical as it caused anxiety in many participants.
● To avoid being unethical, these are the ethics rules for studies:
1. Informed consent
2. Do no harm
3. Debrief (Explain)
4. Confidentiality (Keep information about participants secret)
5. Right to withdraw (The participants can leave at any time)
● Deception is ethically okay because that might be needed in instances where the subject
should not know what is being studied.

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