1.1 Introducing Psychology

The Historical Progression of Psychology

There are many theoretical approaches in psychology designed to explain certain behaviors. Some of the earliest approaches to explaining behavior in psychology include structuralism and functionalism.

Structuralism

Wilhelm Wundt combined physiology and philosophy to create psychology and established the first psychology lab in Germany (1879). He believed in introspection and structuralism.

Structuralism says that structure is more important than function. Structuralists believed that the mind must be broken into elements to understand the brain and its functions. With the use of introspection 🤔 (looking inward), people try to understand the thoughts or emotions they are experiencing at the time.

For structuralism to work, the subject would have to be very intelligent and verbal in order to describe their sensations, images, and feelings in certain moments. Also, introspection proved unreliable since the results varied from person to person. As a result, the impact of introspection waned, as did structuralism.

Functionalism

Functionalism came after structuralism and was created to understand how the conscious mind is related to behavior. Functionalists, such as William James, wanted to know how the mind affected what people did.

Early Behaviorism

Early Behaviorism was the study of observable events. This theory shifted psychology from a study of the unconscious and conscious mind to a more science-based study based on observable events.

John Watson was a behavioral psychologist who studied observable behaviors and led the Little Albert experiment, where he trained an 11-month-old boy to fear a white rat. 🐭 The boy was not initially afraid of the rat, but when the white rat was paired with a loud sound, the boy would show signs of distress. Eventually, the boy began to cry when just seeing the white rat without the sound. Watson believed that observable events are the only events that can be proven true, unlike studying the conscious, where results are not verifiable.

Gestalt Psychology

Gestalt psychology says that the whole is different than the sum of its parts. Gestalt psychology looks at the mind and behavior as a whole. It suggests that human minds do not focus on small components. Instead, humans see the greater whole. Examples of Gestalt principles are below and discussed in further detail in Unit 3.

Image courtesy of ResearchGate.

Psychological Approaches

The psychoanalytic/Psychodynamic approach focuses on the study of the unconscious mind. It states that behavior is determined by past experiences. Sigmund Freud is the key individual that used this approach, and he built his theories based on it.

The humanistic approach believes that humans have free will and the ability to grow. All individuals are striving to reach self-actualization and their greatest potential with this approach. 🌱

The evolutionary approach uses evolutionary biology to explain human behavior. Also, it looks at how natural selection due to variable traits promotes the survival of genes. An evolutionary psychologist may study how anger could be a gene inherited from our ancestors.

The biological perspective states that behavior is based on physical processes, such as those relating to the brain, hormones, and other chemicals.

The cognitive approach states that thought processes impact the way people behave. A cognitive psychologist may study how an emotion, such as fear, affects one’s thinking.

The biopsychosocial perspective acknowledges the person as a whole and tries to look at all of the patient's circumstances. It looks at biological, psychological, and social factors to understand a person’s behavior.

The sociocultural approach studies how thinking and behavior vary across cultures and situations. A sociocultural psychologist may study how expressions of sadness vary across cultures.

Subfields of Psychology

Biological psychology states that physical processes shape behavior. For example, a biological psychologist might say that anger is due to a certain hormonal balance in the brain. 😡

Clinical psychology is a section of psychology focused on assessing and treating mental, emotional, and behavioral disorders.

Cognitive psychology studies the mental processes associated with thinking, knowing, and communicating. 🤔

Counseling psychology focuses on personal issues that are not classified as mental disorders. These types of therapists help people cope with challenges and crises in life. For example, they can help a student with social or academic struggles. They could even help an individual with marital issues.

Developmental psychology studies social, physical, and cognitive changes throughout the lifespan. So, they study from “womb to tomb.” 👶

Educational psychology is the study of how psychological processes can impact and improve learning and teaching. 👩🏽‍🏫

Experimental psychology uses the experimental method to examine relationships between behavior and the mind.

Industrial-organizational psychology studies the relationships between work and people in order to help companies increase productivity, boost morale, and select and train employees.

Personality psychology is the study of how personality affects the way people think and behave.

Psychometric psychology focuses on psychological measurement and is concerned with the design of psychological examinations.

Social psychology studies how humans are influenced by one another and how we relate and think about each other. 👫

Positive psychology focuses on making human existence more fulfilling, rather than focusing on the treatment of mental illness. It promotes strengths and virtues to improve the lives of people and communities.

Key Terms to Review (30)

Biological Perspective: The biological perspective in psychology is a way of looking at psychological issues by studying the physical basis for animal and human behavior. It's one of the major perspectives in psychology and involves such things as studying the brain, immune system, nervous system, and genetics.

Biological Psychology: Biological psychology, also known as biopsychology or psychobiology, is a field in psychology that examines the physical basis for behaviors and mental states, looking specifically at the roles of genetics and the brain.

Biopsychosocial Perspective: The biopsychosocial perspective is an integrated approach that considers biological, psychological, and social factors in health and illness.

Clinical Psychology: Clinical psychology is a branch of psychology that focuses on diagnosing and treating mental, emotional, and behavioral disorders.

Cognitive Approach: The cognitive approach in psychology is a way of understanding human behavior that focuses on how we think. It suggests that our thought processes affect the way we behave.

Cognitive Psychology: Cognitive psychology is the scientific study of mind as an information processor - it involves studying how people perceive, remember, think about information & solve problems.

Counseling Psychology: A branch of psychology that focuses on facilitating personal and interpersonal functioning across the life span with a focus on emotional, social, vocational, educational, health-related, developmental, and organizational concerns.

Developmental Psychology: The scientific study of how and why human beings change over the course of their life. It's concerned with infants through old age.

Early Behaviorism: Early Behaviorism is a theory suggesting that all behaviors are acquired through conditioning. It proposes that our responses to environmental stimuli shape our actions.

Educational Psychology: A field in psychology that studies how people learn in educational settings, the effectiveness of educational interventions, the psychology of teaching, and the social psychology of schools as organizations.

Evolutionary Approach: The evolutionary approach in psychology applies principles of evolution, including natural selection and survival of the fittest, to explain psychological processes and phenomena.

Experimental Psychology: Experimental psychology is the branch of psychology that utilizes scientific methods to investigate how and why humans think, feel, and behave the way they do.

Functionalism: Functionalism is a psychological philosophy that considers mental life and behavior in terms of active adaptation to the person's environment. It focuses on how our mental and behavioral processes function - how they enable us to adapt, survive, and flourish.

Gestalt Psychology: Gestalt Psychology is a school of psychology based upon the idea that we experience things as unified wholes. This approach to psychology emerged in Germany in the early 20th century as an alternative to the traditional structuralist approach.

Humanistic Approach: This is a psychological perspective that emphasizes the study of the whole person and believes individuals have free will. It focuses on human potential and encourages self-exploration rather than studying behavior in response to a stimulus.

Industrial-Organizational Psychology: Industrial-organizational psychology applies psychological theories and principles to organizations. It focuses on increasing workplace productivity and related issues such as physical and mental well-being of employees.

Introspection: Introspection is self-examination or observation of one's own emotional states or thought processes. It involves looking inward to analyze one's inner thoughts and feelings.

John Watson: John Watson was an American psychologist who is often referred to as the father of behaviorism, a school of thought in psychology that emphasizes the importance of observable behaviors over internal mental processes.

Little Albert Experiment: The Little Albert experiment was a famous psychology study conducted by John Watson and Rosalie Rayner. They conditioned a small child, Albert, to fear a white rat. They also demonstrated that this fear could generalize to other similar objects.

Personality Psychology: Personality psychology studies personality along with its variation among individuals. It aims to show how people are individually different due to psychological forces.

Positive Psychology: Positive psychology is a branch within psychology that focuses on studying positive emotions, strengths-based character traits, and healthy institutions with an aim towards improving quality life and preventing the pathologies that arise when life is barren and meaningless.

Psychoanalytic/Psychodynamic Approach: This is a psychological perspective that emphasizes the importance of unconscious mental processes and early childhood experiences in shaping behavior, thoughts, and feelings.

Psychometric Psychology: Psychometric psychology is a field of study that focuses on the theory and technique of psychological measurement. This includes the measurement of knowledge, abilities, attitudes, personality traits, and educational achievement.

Self-Actualization: Self-actualization is the process of realizing and fulfilling one's potential and capabilities. It's the highest level of psychological development where personal growth, fulfillment, and accomplishment are sought.

Sigmund Freud: An Austrian neurologist who founded psychoanalysis. He proposed theories about the role of the unconscious mind, childhood experiences, and sexuality in influencing human behavior and development.

Social Psychology: Social psychology is an area within psychology that explores how people's thoughts, feelings, behaviors are influenced by others around them. It studies social interactions including their origins and their effects on individuals.

Sociocultural Approach: The sociocultural approach examines how social and cultural environments influence behavior.

Structuralism: Structuralism is an early school of psychology that used introspection to explore the elemental structure of the human mind.

Wilhelm Wundt: Wilhelm Wundt was a German physician, psychologist, and philosopher who is widely regarded as one of the founders of modern psychology. He established the first laboratory for psychological research at Leipzig University in Germany.

William James: William James was an American philosopher and psychologist who was also trained as a physician. He is often referred to as the father of American psychology. His work laid much of the groundwork for modern theories about consciousness, perception, memory, emotion, etc.

1.2 Research Methods in Psychology

Overview of Research Methods

There are various types of research methods in psychology with different purposes, strengths, and weaknesses.

Examples

Experiment

Whenever researchers want to prove or find causation, they would run an experiment.

An experiment you'll learn about in Unit 9 that was run by Solomon Asch investigated the extent to which one would conform to a group's ideas.

Image Courtesy of Wikipedia.

Each person in the room would have to look at these lines above and state which one they thought was of similar length to the original line. The answer was, of course, obvious, but Asch wanted to see if the "real participant" would conform to the views of the rest of the group.

Asch gathered together what we could call "fake participants" and told them not to say line C. The "real participant" would then hear wrong answers, but they did not want to be the odd one out, so they conformed with the rest of the group and represented the majority view.

In this experiment, the "real participant" was the control group, and about 75% of them, over 12 trials, conformed at least once.

Correlational Study

There could be a correlational study between anything. Say you wanted to see if there was an association between the number of hours a teenager sleeps and their grades in high school. If there was a correlation, we cannot say that sleeping a greater number of hours causes higher grades. However, we can determine that they are related to each other. 💤

Remember in psychology that a correlation does not prove causation!

Survey Research

Surveys are used all the time, especially in advertising and marketing. They are often distributed to a large number of people, and the results are returned back to researchers.

Naturalistic Observation

If a student wanted to observe how many people fully stop at a stop sign, they could watch the cars from a distance and record their data. This is a naturalistic observation since the student is in no way influencing the results.

Case Study

A notable psychological case study is the study of Phineas Gage:

Phineas Cage was a railroad construction foreman who survived a severe brain injury in 1848. The accident occurred when an iron rod was accidentally driven through Gage's skull, damaging his frontal lobes. Despite the severity of the injury, Gage was able to walk and talk immediately after the accident and appeared to be relatively uninjured.

However, Gage's personality underwent a dramatic change following the injury. He became impulsive, irresponsible, and prone to outbursts of anger, which were completely out of character for him before the accident. Gage's case is famous in the history of psychology because it was one of the first to suggest that damage to the frontal lobes of the brain can have significant effects on personality and behavior.

Key Terms to Review (26)

Adderall: Adderall is a prescription medication containing two drugs, amphetamine and dextroamphetamine. It is used for treating attention deficit hyperactivity disorder (ADHD) and narcolepsy.

Association: In psychology, association refers to any connection between thoughts, feelings, or experiences that leads one to recall another. It's often used in learning theories such as classical conditioning and operant conditioning.

Case Studies: Case studies are detailed investigations into one individual or small group. These studies provide rich qualitative data and can offer insights into unique situations that may not be captured in larger-scale research methods.

Cause and Effect: Cause and effect is a relationship between events or things, where one is the result of the other. This is a combination of action and reaction.

Conformity: Conformity refers to adjusting our behavior or thinking to coincide with a group standard or expectation.

Control Group: In an experiment, the control group is the set that does not receive the treatment or intervention and is used as a benchmark to measure how other tested subjects do.

Correlational Studies: Correlational studies measure two variables and examine how they relate to each other without manipulating either one of them.

Cross-Sectional Studies: Cross-sectional studies are observational research methods that analyze data from a population, or a representative subset, at one specific point in time.

Cross-Sectional Study: A cross-sectional study is a type of observational research that analyzes data from a population at one specific point in time—it’s like taking a snapshot of the population.

Ethical Issues: Ethical issues refer to problems or situations requiring a person or organization to choose between alternatives that must be evaluated as right (ethical) or wrong (unethical).

Experiments: Experiments are a type of research method where the researcher manipulates one variable (independent variable) to determine its effect on another variable (dependent variable).

Frontal Lobes: The frontal lobes are areas at the front of each cerebral hemisphere involved with decision-making, problem-solving, control over voluntary movements or activity (motor skills), and complex behaviors such as social interactions and personality expression.

Generalize Results: Generalizing results means applying findings from a sample group in an experiment or study to larger populations outside the study.

Hawthorne Effect: The Hawthorne Effect refers to the alteration of behavior by the subjects of a study due to their awareness of being observed.

Human Development Stages: Human Development Stages refer to distinct phases that individuals pass through from birth until death, including physical, cognitive, and socioemotional changes.

Independent Variables: An independent variable is what researchers manipulate during an experiment to measure its impact on dependent variables.

Longitudinal Studies: Longitudinal studies are research methods that involve repeated observations of the same variables (e.g., people) over long periods of time, often many decades.

Naturalistic Observations: Naturalistic observation is an observational method where researchers observe individuals' behavior in their natural environment without intervention or manipulation.

Personality Change: A personality change refers to a significant shift in a person's established patterns of behavior, thoughts, and emotions. This can be due to various factors such as brain injury, mental health disorders, or life experiences.

Phineas Gage: Phineas Gage was a railroad construction foreman who survived a severe brain injury in the mid-19th century. His case is often studied in psychology because of the dramatic personality changes he experienced after his accident, which provided early evidence for the role of the frontal lobes in personality and behavior.

Realism: In psychology, realism refers to an orientation towards facts and reality, accepting them without distortion by personal feelings or prejudices.

Replicate: In psychology, to replicate means to repeat a research study, often with different participants and in different situations, to see if the basic findings can be observed again.

Research Methods: Research methods are the strategies, tools, and techniques used to collect and analyze data in psychology. They help psychologists understand human behavior and mental processes.

Response Rates: In psychology research, response rates refer to the proportion of people who respond out of the total number asked or surveyed.

Solomon Asch: Solomon Asch was a prominent psychologist best known for his experiments on conformity, where he demonstrated the influence of group pressure on individual behavior.

Survey Research: Survey research is a method of data collection that involves asking a large number of participants a series of questions or completing a questionnaire.

1.3 Defining Psychological Science: The Experimental Method

Types of Research 

Basic Research is performed to learn about something. It is curiosity-driven and used to expand upon knowledge. It doesn't have an immediate objective. An example of basic research would be a study assessing the impacts of caffeine ☕ consumption on the brain. As you can see from the example, the goal is not to solve a problem it is only to increase knowledge about a particular topic. 

Applied Research answers specific questions and is used to solve a problem or do something of practical use. An example of applied research would be trying to find a cure for obsessive-compulsive disorder.

The Scientific Method

Even though you have probably learned this a million times, here is a quick overview:

• First, the researcher would make a theory to try and explain the behavior that we are observing.

• This theory would then produce a hypothesis, or an educated guess/testable prediction.

• However, theories could bias our observations. Think about it: if you want to prove your theory correct, you would try and make it so the results prove it.

• To avoid this bias, psychologists use something called an operational definition.

  • How do you test something if every researcher describes it in a different way, possibly, even, in a biased way?🤔

  • Operational Definitions are statements of the exact procedures used in the study, which would eventually allow other researchers to replicate the research.

  • Here's an example: how would you describe human intelligence?

    • You may have said how smart someone is, measured by their grades, but this is a biased definition. The operational definition would be what an intelligence test (such as an IQ test) measures.

Types of Variables

There are several types of variables in an experiment. There is the independent variable, dependent variable, confounding variables, and control variables.

• The independent variable is the variable that changes in an experiment. For example, a researcher wanted to see how sleep affects performance on a certain exam. The researcher would change the amounts of sleep given to the subjects in order to see any changes. 

• The dependent variable is the effect of the change in the experiment. This is what gets measured. For example, in the earlier example with sleep 😴 and performance on exams, sleep is the independent variable and the performance on the exam is the dependent variable, because performance on the exam “depends” on the independent variable, sleep.

• The confounding variable is an outside influence that changes the effect of the dependent and independent variables. For example, say there is a correlation between crime and the sale of ice cream🍨. As the crime rate increases, ice cream sales also increase. So, one might suggest that criminals cause people to buy ice cream or that purchasing ice cream causes people to commit crimes. However, both are extremely unlikely. 

• The confounding variable includes a new outside variable not present in the original experiment. In our ice cream example, let's look at the weather, which could be the reason for the correlation. Ice cream is more often sold when it is hot outside, and people are more likely to commit crimes when it is hot outside because there is more social interaction. In the winter, people are less likely to buy ice cream, and there is also less social interaction. ☀

• To recall from key topic 1.2, the Hawthorne Effect exists as well. If a researcher is observing people, those people would behave differently when they realize they are being watched, impacting the results of the naturalistic observation.

Image Courtesy of Kiana Matthews.

• The control variable is the variable that's kept the same throughout an experiment. For example, if a researcher wants to see how sleep affects performance on a test, the control variables could be the test, sleeping atmosphere, and the type of bed. These would all be kept the same throughout the research. 

Why do we need a control variable?

Well, then you can prove why something happened without an alternate explanation. You can’t say the type of bed or the difficulty of the test impacted those results if the researcher kept those the same throughout the experiment. 

Cause and Effect

⭐️Remember: Experiments are the only research that can determine cause and effect.

Also, a researcher must use random assignment to demonstrate cause and effect. Random assignment is when participants are assigned to each experimental group with an equal chance ⚖ of being chosen. Don't confuse this with a random sample: each individual in the population has an equal chance of participating in an experiment.

Random assignment is randomly selecting people to be in an experimental group while random sample is randomly selecting people from the population to be in the experiment as a whole. Both random sampling and random assignment ultimately lead to the most accurate results.

Types of Bias

Sampling bias is a result of a flawed sampling process that produces an unrepresentative sample.

Experimenter bias is when researchers influence the results of an experiment to portray a certain outcome. A double-blind procedure is when neither the researcher or the participants know what groups the participants have been assigned to. This helps prevent bias when the researcher is looking over the results.

Common Sense?

Researchers and scientists cannot rely on common sense because of three main concepts:

1. Hindsight Bias: the tendency to believe that you knew what was going to happen, as if you foresaw the event: "I knew it all along."

2. Overconfidence: we are often overconfident in what we find/believe, which misleads others about the truth.

3. We perceive order in events that are completely random. You can see this with coin flips. If you were to ask a group of students to flip a coin 50 times and record data, you'd be able to easily tell who actually did the assignment and who thought they could just make up the results. Those that actually did the assignment would have had long chains of heads or long chains of tails (HHHHHHH/TTTTTTT) while those that didn't would just alternate between the two (HTHTHTHHTTHTHT). We are generally unable to understand randomness since we always try to make sense of it.

Key Terms to Review (19)

Applied Research: Applied research refers to scientific study and research that seeks to solve practical problems. This kind of research plays an important role in solving everyday issues that often have an impact on life, work, health, and overall well-being.

Basic Research: Basic research is a type of scientific study aimed at expanding knowledge and understanding fundamental concepts. It's not necessarily intended for immediate, practical application.

Cause and Effect: Cause and effect is a relationship between events or things, where one is the result of the other. This is a combination of action and reaction.

Confounding Variables: These are factors other than the independent variable that may cause a result in an experiment, making it difficult to determine if the results were due to the independent variable or these other factors.

Control Variables: Control variables are factors that researchers keep constant to ensure that they do not interfere with the results of an experiment.

Dependent Variable: The dependent variable is what changes when the independent variable changes - it's what you're interested in measuring as a result of your experiment.

Double-Blind Procedure: A double-blind procedure is an experimental method used to eliminate bias. In this setup, neither the participant nor the experimenter knows which group (control or experimental) the participant is in.

Experimenter Bias: Experimenter bias refers to the possibility that a researcher's expectations might skew the results of an experiment.

Hawthorne Effect: The Hawthorne Effect refers to the alteration of behavior by the subjects of a study due to their awareness of being observed.

Hindsight Bias: Hindsight bias is the tendency to believe, after learning an outcome, that one would have foreseen or predicted it.

Hypothesis: A hypothesis is an educated guess or proposition made as a basis for reasoning or research without any assumption of its truth. It's testable and falsifiable statement about two or more variables related in some way.

Independent Variable: The independent variable is the factor in an experiment that a researcher manipulates to see if it has any effect on the outcome.

Operational Definitions: An operational definition describes how to measure a variable or define a term. It outlines the procedures used in research.

Overconfidence: Overconfidence refers to the tendency of an individual to overestimate their abilities and knowledge, leading them to make decisions without considering potential risks or negative outcomes.

Random Assignment: Random assignment is a method used in experiments to ensure that each participant has an equal chance of being placed into any group. This helps to eliminate bias and make sure the results are due to the variable being tested, not differences between groups.

Random Sample: A random sample is a subset of individuals randomly selected by researchers from a larger population. Each individual has an equal probability of selection which helps ensure that the sample represents the population well.

Sampling Bias: Sampling bias occurs when some members of your intended population have lower sampling probability than others or when there's systematic difference between samples taken at different times or places. It can lead to misleading results.

Scientific Method: The scientific method is a systematic procedure that researchers use to conduct experiments. It involves observing, forming questions, making predictions, doing experiments, and developing theories.

1.4 Selecting a Research Method

When selecting a research method, the researcher should write down their goals and what their research question is.

Selecting a research method depends on what a researcher wants to show or prove. For example, if a researcher only wants to show a correlation between two variables, then an experiment would not be optimal. If a researcher wants to show cause and effect between two variables, then an experiment is the best method. 

When performing any research, the researcher should be sure of their results to ensure that they show true relationships. 

Validity

Selecting a research method also depends on the validity of the experiments. There are two types of validity: external validity and internal validity.

• External validity refers to how generalizable the results of the experiment are. For example, if the study on a drug is done on an Asian, middle-aged, average-weight man with high blood pressure, can the results be generalized to the population? 

• Internal validity is when a study shows a truthful cause-and-effect relationship and the researcher is confident that the changes in the dependent variable were produced only by the independent variable. A confounding variable hurts the internal validity because it creates lower confidence in the research conclusion.

Confounding Variables

Confounding variables limit the confidence that researchers have in their conclusions. To recall from the last key topic, the confounding variable is an outside influence (variable) that changes the effect of a dependent and independent variable. For example, we looked at the correlation between crime ⛓ and the sale of ice cream 🍨. As the crime rate increases, ice cream sales also increase. So, one might suggest that criminals cause people to buy ice cream or that purchasing ice cream causes people to commit crimes. However, both are extremely unlikely.

Image Courtesy of Pinterest.

When taking a look at this graphic above, smoking becomes a very clear confounding variable when thinking about what causes many chronic illnesses and cancer. It may look like coffee is directly causing pancreatic cancer, since you are focused on it and are measuring its effects, but smoking contributes as well, without you realizing. That rings the question: how accurate is it that exposure to coffee leads to pancreatic cancer or that the two are even correlated? This is why confounding variables are so important!

Here is a quick reminder of the different research methods and their strengths/weaknesses:

Table Courtesy of Myers AP Psychology Textbook - 2nd Edition

Practice AP Question

The following prompt is from the 2013 AP Psychology Exam (#1).

1. In response to declining reading scores in local schools, John wrote an editorial suggesting that schools need to increase interest in reading books by providing students with incentives. Based on research showing a relation between use of incentives and student reading, he recommended providing a free pizza coupon for every ten books a student reads. 🍕

This question had several parts, but let's relate it to research methods.

Could we trust his argument? Does he have the right evidence?

Not really, right? He never ran an experiment and actually implied causation. That is something we could never do. Association does not equal causation.

Just because he found a "relation" between incentives and student reading, it doesn't mean that using incentives could increase student reading. Therefore, we could easily refute John's argument and prove that providing an incentive would not help increase interest in reading books. 📚

⭐️When taking a look at a free-response question on the AP Psychology exam, be sure to look out for words such as "caused" or "correlated." You always want to see what is being implied and test its accuracy. Here, we saw the word "relation," and quickly thought correlation does not equal causation.

Key Terms to Review (12)

Case Studies: Case studies are detailed investigations into one individual or small group. These studies provide rich qualitative data and can offer insights into unique situations that may not be captured in larger-scale research methods.

Cause and Effect: Cause and effect is a relationship between events or things, where one is the result of the other. This is a combination of action and reaction.

Confounding Variables: These are factors other than the independent variable that may cause a result in an experiment, making it difficult to determine if the results were due to the independent variable or these other factors.

Correlation: Correlation refers to the statistical relationship between two variables. If one variable changes, there tends to be a consistent change in the other variable too.

Correlational Research Method: Correlational research methods involve measuring two variables and analyzing how they relate to each other - whether they move together (positive correlation), move in opposite directions (negative correlation), or have no relationship (zero correlation).

Descriptive Research Method: This method involves observing and describing behavior without manipulating variables. It often involves naturalistic observations, surveys, and case studies.

External Validity: External validity refers to how well the results of a study can be generalized or applied to other situations and people.

Internal Validity: Internal validity refers to how well an experiment is done, especially whether it avoids confounding (more than one possible independent variable [cause] acting at the same time).

Naturalistic Observations: Naturalistic observation is an observational method where researchers observe individuals' behavior in their natural environment without intervention or manipulation.

Research Question: A research question is a clear, focused, concise, complex and arguable question around which you center your research. It's the question to which you want to find an answer through your study.

Surveys: Surveys are a research method that involves asking a large number of people questions about their thoughts, feelings, behaviors, or attitudes.

Validity: Validity refers to the extent to which a test or experiment measures what it is supposed to measure

1.5 Statistical Analysis in Psychology

Types of Statistics

Descriptive statistics involves the use of numerical data to measure and describe the characteristics of groups, and this includes measures of central tendency and variation. We'll be focusing on descriptive statistics in this study guide! It does not involve making inferences about a population based on sample data.

Inferential statistics, on the other hand, involves using statistical methods to make inferences about a population based on data. It allows you to draw conclusions about a population based on the characteristics of a sample. Specifically, it provides a way to see validity drawn from the results of the experiment🧪🔬.

Therefore, descriptive statistics describe the data, while inferential statistics tell us what the data means.

Summarizing Data

When one has a ton of data, how do they begin to go through it? Typically, a researcher would construct and interpret a graph with their data, and they use descriptive statistics to do so. 📈

Measures of Central Tendency

Measures of central tendency are statistical values that represent the center or typical value of a dataset. The three most commonly used measures of central tendency are the mean, median, and mode.

• The mean is the average of a set of scores. You can calculate the mean by summing all of the values in a dataset and dividing by the total number of values. The mean is sensitive to outliers, or unusually large or small values, and can be affected by them.

• The median is the middle score of distribution, separating the higher half of the data from the lower half. The median is not affected by outliers and can be a better measure of central tendency when the dataset contains outliers.

• The mode is the most frequently recurring score in a dataset. A dataset can have one mode, more than one mode, or no mode. If two scores appear the most frequently, the distribution is bimodal. If three or more scores appear most frequently, the distribution is multimodal.

Let's practice calculating the three measures of central tendency, mean, median, and mode, using the following data set: 5, 10, 5, 7, 12, 15, 18

The easiest to spot is the mode: which value, if any, appears more often than others? Here, we can see 5 twice, so the mode of this dataset is 5.

Then, you may want to calculate the mean by adding all of these data values and dividing by the total. Since we have seven values, we have to divide by seven: (5 + 10 + 5 + 7 + 12 + 15 + 18)/7 = 10.286

The median is the middle of the data set when the numbers are in order. Make sure you always put them in order!! If you do so here, you will find that the median is 10.

Measures of Variation

Measures of variation describe how spread out or dispersed the values in a dataset are. The most commonly used measure of variation is the standard deviation, which is a measure of how much the values in a dataset deviate from the mean. It is basically used to assess how far the values are spread below and above the mean. A dataset with a low standard deviation has values that are relatively close to the mean, while a dataset with a high standard deviation has values that are more spread out.

Another, less complex, measure of variation you should be familiar with for this course is the range of a dataset. Range is just the difference between the highest and lowest values in the dataset.

Correlation

The correlation coefficient is a statistical measure that describes the strength and direction of the relationship between two variables. It can range from -1 to 1. A value of -1 indicates a strong negative relationship, a value of 1 indicates a strong positive relationship, and a value of 0 indicates no relationship.

You can simply think of it as a measure of how well two variables are correlated, and the closer it is to -1 or +1, the stronger the correlation.

Positive Correlation

Positive correlation shows that as one variable increases ⬆, the other variable increases ⬆. For example, a positively correlated group may show that as height increases, weight increases as well.

Image courtesy of Expii

Negative Correlation

Negative correlation shows that as one variable increases ⬆, the other decreases ⬇. An example of a negative correlation could be how as the number of hours of sleep increases, tiredness decreases.

Image courtesy of Expii

No Correlation

Image courtesy of Expii.

Remember, correlation does not imply causation, even if the correlation coefficient is -1 or +1. You must run an experiment to prove there is causation.

Skews

A frequency distribution is a breakdown of how the scores fall into different categories or ranges. There are several types of frequency distributions:

• 🔔A normal distribution is a bell-shaped frequency distribution that is symmetrical about the mean. We'll delve into this deeper, but graph (b) on the image below shows a normal distribution!

• 2⃣A bimodal distribution is a frequency distribution with two peaks. This occurs when the dataset has two distinct groups of values that occur with different frequencies.

• 👍A positively skewed distribution has a tail extending to the right (towards larger values). This occurs when the dataset has a few unusually large values that pull the mean to the right. Graph (a) in the image below is a positively skewed distribution, where the mean is greater than the median.

• 👎A negatively skewed distribution has a tail extending to the left (towards smaller values). This occurs when the dataset has a few unusually small values that pull the mean to the left. Graph (c) in the image below is a negatively skewed distribution, where the median is greater than the mean.

It might be hard to remember which way the skew is. If the tail on the right is longer like it is in (a), then it's a skew to the right. If the tail on the left is longer like it is in (c), then it's a skew to the left.

Image courtesy of ResearchGate

Normal Distributions

The normal curve, or (b) in the above image, is the only one you have to really be familiar with for this course. There are two important values that you should memorize: 68% and 95%.

Image from Myers' AP Psychology Textbook; 2nd Edition

This is a normal curve that includes data about intelligence📖. Basically, 68% of the data falls within one standard deviation of the mean. Here, one standard deviation is equivalent to 15, so the data falls between 85 and 115, or +- 15 points of 100.

95% of the data falls within two standard deviations of the mean. Since 2 standard deviations are equal to 30, the data falls between 70 and 130, or +-30 points of 100.

Another term that you should be somewhat familiar with is statistical significance, or the likelihood that something occurs by chance😲. If something is statistically significance, it did not occur by chance (some outside factor influenced the data). If something isn't statistically significant, it occurred completely by chance. To determine this, you would compare the mean of the control group and the mean of the experimental group.

Practice AP FRQ

The following question is taken from the College Board website (2017 AP Exam - Part B of #1).

A study was conducted to investigate the role of framing on concern for healthy eating🍏. Each participant (N = 100) was randomly assigned to one of the two conditions. In the first condition, the participants read an article indicating that obesity is a disease🦠. Participants in the second condition read an article indicating that obesity is the result of personal behaviors and decisions.

Participants were asked to indicate how important it would be for them to eat a healthy diet. Scores ranged from 1 (not very important) to 9 (very important). The results are presented in the table below.

Operationally define the dependent variable.

• What makes the study experimental rather than correlational?

• What is the most appropriate conclusion the researchers can draw about the relationship between the variables in the study? 

The scoring guidelines provide the rubric for this question. You should be able to answer all three parts. If not, just go through this unit’s guides one more time and you’ll nail this FRQ.

Key Terms to Review (22)

Bimodal Distribution: A bimodal distribution occurs when two different values appear most frequently (modes) in the data set.

Correlation Coefficient: The correlation coefficient measures the strength and direction of a linear relationship between two variables on a scatterplot. It ranges from -1 to 1 where -1 indicates perfect negative correlation, 0 indicates no correlation, and 1 indicates perfect positive correlation.

Descriptive Statistics: Descriptive statistics are numerical data used to measure and describe characteristics of groups. They do not allow us to make conclusions beyond the data we have analysed or reach conclusions regarding any hypotheses we might have made.

Frequency Distribution: Frequency distribution refers to how often something happens within certain ranges or intervals for a set of data points.

Inferential Statistics: Inferential statistics are procedures used that allow researchers to infer or generalize observations made with samples to the larger population from which they were drawn.

Mean: The mean is simply the sum of all values in a dataset divided by the total number of values. It's often referred to as the "average."

Measures of Central Tendency: Measures of central tendency are statistical indicators that identify the center, or average, of a data set. These measures include mean, median, and mode.

Measures of Variation: Measures of variation describe how spread out or scattered the values in a data set are. They include range, variance, and standard deviation among others.

Median: The median is defined as the middle value when all values within a dataset are arranged from smallest to largest. If there is an even number of observations, then there is no single middle value; so we take an average (mean) between two middle numbers instead.

Mode: The mode is the most frequently occurring score in a set of given numbers.

Multimodal Distribution: A multimodal distribution is a probability distribution with more than one peak, or "mode." This means that there are multiple values that appear most frequently in the data set.

Negative Correlation: A negative correlation is a relationship between two variables in which one variable increases as the other decreases.

Negatively Skewed Distribution: A negatively skewed distribution is a type of distribution in which more data values fall to the right side (higher end) of the distribution graph, with the tail on the left side (lower end).

No Correlation: No correlation exists when there is no relationship between two variables; changes in one do not affect changes in another.

Normal Distribution: A normal distribution, also known as a bell curve, is a statistical concept that refers to a type of continuous probability distribution for a real-valued random variable. In this distribution, most of the data falls near the mean (average), with frequencies decreasing away from the mean.

Outliers: An outlier is an observation that lies an abnormal distance from other values in a random sample from a population.

Positive Correlation: Positive Correlation occurs when both variables increase together or decrease together; as one variable increases, so does the other.

Positively Skewed Distribution: A positively skewed distribution is a type of distribution where the values are more spread out on the right side (tail) of the distribution graph. This means that there are some unusually high values in your data.

Range: In statistics, range refers to the difference between the highest and lowest scores in a data set.

Standard Deviation: Standard deviation is a measure used to quantify the amount of variation or dispersion in a set of values. It tells us how much on average scores deviate from their mean value.

Statistical Significance: Statistical significance refers to whether any differences observed between groups being studied are "real" or if they’re likely due just to chance. It's often determined by p-values less than 0.05.

Summarizing Data: Summarizing data involves simplifying collected information into smaller, understandable parts. This can involve using measures such as averages, percentages, or graphs.

1.6 Ethical Guidelines in Psychology

What if stress has to be added to run an experiment? Every experiment has some sort of added stress, but how do we make sure that the potential risk to participants does not outweigh the benefits of the study? How can psychological ethics allow us to approach discussions about reasonable harm?

For example, consider a study on anxiety. The research team may need to induce anxiety in a research participant for their study, but ethics dictate how distress can be caused in a way that minimizes harm and upholds ethical values. Experiments fail if participants are biased with prior knowledge of the experimental procedure and goals, so the ethical guidelines of psychology inform researchers how to conduct experimental research ethically.

Ethical Guidelines

These ethical and legal guidelines provided by the American Psychological Association protect research participants from unethical practices.

The ethical guidelines on human research are: 

• Informed Consent (participants must agree to participate)

• Deception (If deception is used, it must not be done in a way that invalidates informed consent) 

• Deception debriefing (If deception was used, the researchers must explain the true purpose of the experiment after it has occurred)

• Protection from harm or discomfort

• Anonymity (information about the participant will be held a secret)

• Coercion (participants cannot be coerced to give consent to be in any study)

There are a few committees that review experiments before they are conducted to ensure that these guidelines are put in place and participants are protected:

• The Institutional Review Board (IRB) is a committee that reviews research studies involving humans for ethics.

• The Institutional Animal Care and Use Committee (IACUC) reviews research studies involving animals for ethics violations. 🐶 🐱

Unethical Experiments

In the past, there have been experiments that are now considered unethical. With these guidelines and precautions now in place, we are hoping to avoid other experiments like the Milgram Experiment and Harry Harlow's monkey experiment.

The Milgram Experiment

The Milgram Experiment is a very famous demonstration showing how people will obey authority figures even when they disagree. Subjects were instructed to sit in a chair and ask a learner, who was actually working with Milgram, to list pairs of words. If the learner got it wrong, a scientist would instruct the subject to deliver an electric shock to the learner.

It was later found that this experiment had several ethical issues. Although the learner was not actually shocked, the authority made the subject believe that they delivered electrical charges that were potentially fatal. Thus, the subject experienced the trauma of hurting another person. The participants were both harmed and deceived, especially as the debriefing did not include that the learner was never actually punished.

Harry Harlow's Monkey Experiment

Harlow and his wife Margaret bred rhesus monkeys for their research in learning. To prevent the spread of infection, they began separating young monkeys from their mothers early on. These young monkeys were typically put in a sterile cage with a baby blanket for warmth. Interestingly, Harlow noticed that when the blanket was removed to be laundered, the young monkeys became distressed.

This observation contradicted the theory that attachment stems from the need for nourishment. The blanket clearly offered no food or physical nourishment to the baby monkey, but they became attached to it nonetheless. Why was this? According to Harlow, this was because of the contact comfort the blanket provided.

To test this theory, an astoundingly unethical experiment was designed. Be warned that the following experiment contains elements of animal cruelty.

Harlow created two types of artificial mothers: one was a bare wire cylinder with a wooden head and an attached bottle for feeding (yes, it was as terrifying as it sounds). The other “mother” was wrapped in terry cloth and provided no nourishment. If, in fact, attachment bonds form from the infant’s need for nourishment, then the young monkeys should prefer the wire mother with the attached bottle.

Image Courtesy of Verywell Mind.

The results suggested otherwise. Young rhesus monkeys presented with both mothers overwhelmingly preferred the comfort of the terry cloth one over the wire one, despite the fact that the cloth mother provided no food. 

When the babies became stressed, they would cling to the cloth mother for comfort. When exploring, they would use the cloth mother as a secure base, returning to her every so often after venturing out. 

The experiments became even more unethical. Harlow began to sequester young monkeys for months or years at a time with no source of attachment or interaction—only food and drink. These neglected monkeys became completely catatonic and indifferent toward their environment. In adulthood, they could not properly bond or relate with other monkeys. Female monkeys could not get pregnant since they had no interest in social interaction. Harlow had to artificially inseminate these females in order for them to reproduce. 

Sadly, Harlow observed that these neglected female monkeys completely ignored their babies and neglected to feed them. In some cases, the mothers even injured or killed their babies. The implication was clear: these neglected mothers could not properly love or bond with their babies.

Key Terms to Review (15)

American Psychological Association (APA): The APA is a scientific and professional organization that represents psychology in the United States. It's responsible for setting ethical guidelines for psychological research.

Anonymity: Anonymity in psychology refers to the practice of ensuring that all information collected from a participant in a study is not linked to their identity, thus protecting their privacy.

Attachment Bonds: Attachment bonds refer to the deep, enduring emotional connection that forms between individuals, typically between a child and caregiver. This bond significantly influences the child's development and ability to form relationships in the future.

Coercion: Coercion involves forcing someone into doing something against their will, often through threats or manipulation. In psychological research, it's unethical to coerce someone into participating in a study.

Contact Comfort: Contact comfort refers to the physical and emotional comfort that an infant receives from being in physical contact with its mother or primary caregiver.

Deception: In psychology, deception refers to the act of misleading or lying to participants about the true purpose or nature of a study.

Deception Debriefing: Deception debriefing involves explaining any deceptive elements and revealing the true purpose of the study to participants after it has concluded.

Ethical Guidelines: These are rules set by professional organizations that govern the conduct of its members and provide a framework for ethical decision making.

Harry Harlow's Monkey Experiment: A series of experiments conducted by psychologist Harry Harlow in the 1950s and 1960s on rhesus monkeys to demonstrate the importance of care-giving and companionship in social development and cognitive function.

Informed Consent: Informed consent is an ethical principle requiring that research participants be told enough to enable them to choose whether they wish to participate.

Institutional Animal Care and Use Committee (IACUC): The IACUC is a self-regulating entity that, according to U.S. federal law, must be established by institutions that use laboratory animals for research or instructional purposes to oversee and evaluate all aspects of the institution's animal care and use program.

Institutional Review Board (IRB): The IRB is an administrative body established to protect the rights and welfare of human research subjects recruited for participation in activities such as biomedical and behavioral research.

Milgram Experiment: A series of psychological experiments conducted by Stanley Milgram which measured the willingness of participants to obey an authority figure who instructed them to perform acts conflicting with their personal conscience.

Protection from Harm or Discomfort: This is an ethical principle in psychology that ensures participants are not subjected to physical or psychological harm during a study.