1.1 Psychology as a Science

Learning Objectives

  1. Explain why using our intuition about everyday behaviour is insufficient for a complete understanding of the causes of behaviour.
  2. Describe the difference between values and facts and explain how the scientific method is used to differentiate between the two.

Despite the differences in their interests, areas of study, and approaches, all psychologists have one thing in common: they rely on scientific methods. Research psychologists use scientific methods to create new knowledge about the causes of behaviour, whereas psychologist-practitioners, such as clinical, counselling, industrial-organizational, and school psychologists, use existing research to enhance the everyday life of others. The science of psychology is important for both researchers and practitioners.

Of all of the sciences, psychology is probably the one that most non-scientists feel they know the most about. Because psychology is concerned with people and why they do what they do, we are all “intuitive’ or “naive” psychologists. We rely on common sense, experience, and intuition in understanding why people do what they do. We all have an interest in asking and answering questions about our world, and in making sense of ourselves and other people. We want to know why things happen, when and if they are likely to happen again, and how to reproduce or change them. Such knowledge enables us to predict our own behaviour and that of others. We may even collect data (i.e., any information collected through formal observation or measurement) to aid us in this undertaking. It has been argued that people are “everyday scientists” who conduct research projects to answer questions about behaviour (Nisbett & Ross, 1980). When we perform poorly on an important test, we try to understand what caused our failure to remember or understand the material and what might help us do better the next time. When our good friends Monisha and Charlie break up, despite the fact that they appeared to have a relationship made in heaven, we try to determine what happened. When we contemplate the rise of terrorist acts around the world, we try to investigate the causes of this problem by looking at the terrorists themselves, the situation around them, and others’ responses to them.

The problem of intuition

The results of these “everyday” research projects teaches us about human behaviour. We learn through experience what happens when we give someone bad news, that some people develop depression, and that aggressive behaviour occurs frequently in our society. We develop theories to explain all of these occurrences; however, it is important to remember that everyone’s experiences are somewhat unique. My theory about why people suffer from depression may be completely different to yours, yet we both feel as though we are “right.” The obvious problem here is that we cannot generalize from one person’s experiences to people in general. We might both be wrong!

The problem with the way people collect and interpret data in their everyday lives is that they are not always particularly thorough or accurate. Often, when one explanation for an event seems right, we adopt that explanation as the truth even when other explanations are possible and potentially more accurate. Furthermore, we fall victim to confirmation bias; that is, we tend to seek information that confirms our beliefs regardless of the accuracy of those beliefs and discount any evidence to the contrary. Psychologists have found a variety of cognitive and motivational biases that frequently influence our perceptions and lead us to draw erroneous conclusions (Fiske & Taylor, 2007; Hsee & Hastie, 2006; Kahneman, 2011). Even feeling confident about our beliefs is not an indicator of their accuracy. For example, eyewitnesses to violent crimes are often extremely confident in their identifications of the perpetrators of these crimes, but research finds that eyewitnesses are no less confident in their identifications when they are incorrect than when they are correct (Cutler & Wells, 2009; Wells & Hasel, 2008). In summary, accepting explanations without empirical evidence may lead us to faulty thinking and erroneous conclusions. Our faulty thinking is not limited to the present; it also occurs when we try to make sense of the past. We have a tendency to tell ourselves “I knew it all along” when making sense of past events; this is known as hindsight bias (Kahneman, 2011). Thus, one of the goals of psychology education is to make people become better thinkers, better consumers of ideas, and better at understanding how our own biases get in the way of true knowledge.

Why psychologists rely on empirical methods

All scientists, whether they are physicists, chemists, biologists, sociologists, or psychologists, use empirical methods to study the topics that interest them. Empirical methods include the processes of collecting and organizing data and drawing conclusions about those data. The empirical methods used by scientists have developed over many years and provide a basis for collecting, analyzing, and interpreting data within a common framework in which information can be shared. We can label the scientific method as the set of assumptions, rules, and procedures that scientists use to conduct empirical research.

Although scientific research is an important method of studying human behaviour, not all questions can be answered using scientific approaches. Statements that cannot be objectively measured or objectively determined to be true or false are not within the domain of scientific inquiry. Scientists therefore draw a distinction between values and facts. Values are personal statements such as “Abortion should not be permitted in this country,” “I will go to heaven when I die,” or “It is important to study psychology.” Facts are objective statements determined to be accurate through empirical study. Examples are “The homicide rate in Canada has been generally declining over the past 45 years” or “Research demonstrates that individuals who are exposed to highly stressful situations over long periods of time develop more health problems than those who are not.”

When we try to find new facts, we express our prediction about what we believe to be true in a hypothesis. An example of a hypothesis would be “People who eat fruits and vegetables daily have better health than people who never eat fruits and vegetables.” For this to become fact, we must test this hypothesis in research and show the evidence that supports it. This is a testable hypothesis, because it would be possible to do the research. It is also falsifiable, meaning that if our prediction is wrong, and eating fruits and vegetables daily does not lead to better health, we will have the data to show us that we are wrong.

Ideas or values are not always testable or falsifiable: science can neither prove nor disprove them. For example, the famous Viennese neurologist Sigmund Freud, father of psychoanalysis, believed that the unconscious part of our mind is ultimately responsible when we experience anxiety, depression, and other negative emotions. He thought that emotional conflicts and adverse childhood experiences became lodged in the unconscious because consciously acknowledging them was threatening to our sense of wellbeing. This theory is built on a largely untestable idea: the existence of an unconscious. Given that by definition we cannot describe it, it is difficult to see how we could prove its existence or its role in our lives. That does not mean that the unconscious does not exist, but as we’ll see, we need to find a way to look for its existence using testable and falsifiable hypotheses.

Although scientists use research to help establish facts, the distinction between values or opinions and facts is not always clear-cut. Sometimes statements that scientists consider to be factual turn out later, on the basis of further research, to be partially or even entirely incorrect. Although scientific procedures do not necessarily guarantee that the answers to questions will be objective and unbiased, science is still the best method for drawing objective conclusions about the world around us. When old facts are discarded, they are replaced with new facts based on new and correct data. Although science is not perfect, the requirements of empiricism and objectivity result in a much greater chance of producing an accurate understanding of human behaviour than is available through other approaches.

Levels of explanation in psychology

The study of psychology spans many different topics at many different levels of explanation. Lower levels of explanation are more closely tied to biological influences, such as genes, neurons, neurotransmitters, and hormones, whereas the middle levels of explanation refer to the abilities and characteristics of individual people, and the highest levels of explanation relate to social groups, organizations, and cultures (Cacioppo, Berntson, Sheridan, & McClintock, 2000).

The same topic can be studied within psychology at different levels of explanation, as shown in the table below. For instance, the psychological disorder known as depression affects millions of people worldwide and is known to be caused by biological, social, and cultural factors. Studying and helping alleviate depression can be accomplished at low levels of explanation by investigating how chemicals in the brain influence the experience of depression. This approach has allowed psychologists to develop and prescribe drugs, such as Prozac, which may decrease depression in many individuals (Williams, Simpson, Simpson, & Nahas, 2009). At the middle levels of explanation, psychological therapy is directed at helping individuals cope with negative life experiences that may cause depression. At the highest level, psychologists study differences in the prevalence of depression between men and women and across cultures. The occurrence of psychological disorders, including depression, is substantially higher for women than for men, and it is also higher in Western cultures, such as in Canada, the United States, and Europe, than in Eastern cultures, such as in India, China, and Japan (Chen, Wang, Poland, & Lin, 2009; Seedat et al., 2009). These sex and cultural differences provide insight into the factors that cause depression. The study of depression in psychology helps remind us that no one level of explanation can explain everything. All levels of explanation, from biological to personal to cultural, are essential for a better understanding of human behaviour.


Table 1.1. Levels of explanation
Level of Explanation Underlying Process Examples
Lower Biological
  • Depression is, in part, genetically influenced.
  • Depression is influenced by the action of neurotransmitters in the brain.
Middle Interpersonal
  • People who are depressed may interpret the events that occur to them too negatively.
  • Psychotherapy can be used to help people talk about and combat depression.
Higher Cultural and social
  • Women experience more depression than do men.
  • The prevalence of depression varies across cultures and historical time periods.

Critical thinking in psychology

Rational, objective thinking is a hallmark of science. Scientists need to be able to critically think about a problem or issue from a variety of perspectives, but it is not just scientists who need to be good thinkers. Critical thinking skills allow you to be a good consumer of ideas. Before deciding to buy a car, most people would spend some time evaluating what they wanted to buy, how much money they have to spend, what kind of car has a good safety record, and so on. The same thinking processes can be applied to ideas. These critical thinking processes are not necessarily intuitive. The good thing is that we can be taught what they are and how to use them. Thus, learning to think critically is a skill we can acquire with practise. Carole Wade (1995) outlined eight processes that are used in critical thinking:

  1. Ask questions and be willing to wonder — Curiosity precedes all scientific discoveries and is the basis for acquiring knowledge. For example, suppose you are interested in whether physical exercise is important for mood. Questions you might be wondering about could include: Does getting exercise change your mood? Do people who work out daily feel happier than people who don’t get any exercise? Does the kind of exercise matter? How much exercise makes a difference? How do you measure mood anyway?
  2. Define the problem — We need to think about exactly what we want to know about the connection between exercise and mood. There are many ways to define exercise: it might mean walking every day to some people or lifting weights or doing yoga to others. Similarly, some people might interpret mood to be something fairly fleeting, while other people might think mood refers to clinical depression. We need to define the issue or question we are interested in.
  3. Examine the evidence — Empirical evidence is the kind of support that critical thinkers seek. While you may be aware that a friend or relative felt better when they started running every day, that kind of evidence is anecdotal — it relates to one person, and we don’t know if it would apply to other people. To look for evidence, we should turn to properly conducted studies. In psychology, these are most easily found in a searchable database called PsycINFO that is available through university libraries. PsycINFO contains a vast index of all of the scholarly work published in psychology. Users can often download the original research articles straight from the PsycINFO website.
  4. Analyze assumptions and biases — Whenever we are reasoning about an idea, we are bound to begin with certain assumptions. For example, we might assume that exercise is good for mood because we usually assume that there is no downside to exercise. It helps if we can identify how we feel or think about an idea. All people are prone to some degree to confirmation bias, which is the tendency to look for evidence that supports your belief, while at the same time, discounting any that disconfirms it. This type of bias might be reflected in the social media accounts we follow — we follow people who think like us and do not follow people who might have opposing, although possible valid, points of view.
  5. Avoid emotional reasoning — This process is related to the previous one. It is hard to think about anything in a completely objective manner. Having a vested interest in an issue, or personal knowledge about it, often creates an emotional bias that we may not even be well aware of. Feeling strongly about something does not make us think rationally; in fact, it can be a barrier to rational thinking. Consider any issue you feel strongly about. How easy is it to separate your emotions from your objectivity?
  6. Avoid oversimplification — Simplicity is comfortable, but it may not be accurate. We often strive for simple explanations for events because we don’t have access to all of the information we need to fully understand the issue. This process relates to the need to ask questions. We should be asking ourselves “What don’t I know about this issue?” Sometimes issues are so complex that we can only address one little part. For example, there are likely to be many things that affect mood; while we might be able to understand the connection to some types of physical exercise, we are not addressing any of the myriad other social, cognitive, and biological factors that may be important.
  7. Consider other interpretations — Whenever you hear a news story telling you that something is good for you, it is wise to dig a little deeper. For example, many news stories report on research concerning the effects of alcohol. They may report that small amounts of alcohol have some positive health effects, that abstaining completely from alcohol is not good for you, and so on. A critical thinker would want to know more about how those studies were done, and they might suggest that perhaps moderate social drinkers differ from abstainers in a variety of lifestyle habits. Perhaps there are other interpretations for the link between alcohol consumption and health.
  8. Tolerate uncertainty — Uncertainty is uncomfortable. We want to know why things happen for good reasons. We are always trying to make sense of the world, and we look for explanations. However, sometimes things are complicated and uncertain, or we don’t yet have an explanation for it. Sometimes we just have to accept that we don’t yet have a full picture of why something happens or what causes what. We need to remain open to more information. It is helpful to be able to point out what we don’t know, as well as what we do.

Psychology and pseudoscience

It is important to understand both what psychology is and what it is not. Psychology is a science because it uses and relies on the scientific method as a way to acquire knowledge. Science is an open activity, meaning that results are shared and published. Many scientists conduct research on the same topic, although perhaps from slightly different angles. You can think of scientific knowledge as a snowball — the more knowledge we have, the bigger the snowball, and if it carries on rolling, scientists carry on conducting research at an issue from multiple angles and perspectives. Thus, science is essentially a collaborative process, with all aspects of process and results thrown open to the wider community for consideration and analysis. In science, your conclusions have to be based on empirical evidence, and the merits of the conclusions will have to be judged by peers before they are published. This process is called peer review, and it ensures that what gets published has been reviewed for its adherence to scientific methods and for the accuracy of its conclusions.

Occasionally, we may read a news story or see an advertisement purporting to have information that will change our lives. Such stories often allude to evidence but fail to show where to find it, or they rely on anecdotal rather than empirical evidence. They sometimes use celebrity endorsements and claim that if we do not act immediately to buy their information or product, we will lose out. Typically, these claims are targeted at significant concerns such as weight loss, unhappiness, unspecified pain, and the like — often the very areas that psychologists are attempting to learn more about. Pseudoscience is the term often used to describe such claims; equivalent terms are “bad science” or “junk science.” Fortunately, we can use the critical thinking processes outlined above to evaluate the veracity of claims that seem too good to be true.



Research Focus

Pseudoscience alert: Your handwriting does not reveal your character

One of the common beliefs that people have about personality is that it is revealed in one’s handwriting. Graphology is a pseudoscience that purports to show that aspects of our handwriting reflect aspects of our character. Reader’s Digest (LaBianca & Gibson, 2020) claims to explain the meaning of handwriting characteristics, such as spacing, size of characters, and how you cross your t’s. “If you dot your i’s high on the page, you likely have an active imagination, according to handwriting analysis experts. A closely dotted i is the mark of an organized and detail-oriented mind. If you dot your i’s to the left, you might be a procrastinator, and if you dot your i’s with a circle, you likely have playful and childlike qualities” (LaBianca & Gibson, 2020, “How do you dot your i’s?”).

Graphology has a long history (e.g., Münsterberg, 1915; Downey, 1919) and is related to many other attempts to explain people’s character based on aspects of physical appearance, such as the shape of one’s face, size of one’s hands, or bumps on one’s head (i.e., phrenology). People have always been interested in personality and how to measure, describe, and explain it.

Unfortunately, this attempt to understand people’s personality or career prospects by reading their handwriting has no empirical evidence to support it (Dazzi & Pedrabissi, 2009; Lilienfeld, Lynn, Ruscio, & Beyerstein, 2010). Even though graphology was debunked several decades ago, the Reader’s Digest article on their website in 2020 shows that the belief persists.



Key Takeaways

  • Psychology is the scientific study of mind and behaviour.
  • Commonsense thinking is not always correct.
  • We are not always aware of the errors in reasoning that we make.
  • People are frequently unaware of the causes of their own behaviours.
  • Psychologists use the scientific method to collect, analyze, and interpret evidence.
  • Employing the scientific method allows the scientist to collect empirical data objectively, which adds to the accumulation of scientific knowledge.
  • Psychological phenomena are complex, and making predictions about them is difficult because of individual differences and because they are multiply determined at different levels of explanation.
  • Critical thinking involves a number of processes that can be specified and practised.
  • Pseudoscience often involves claims about topics that psychologists are interested in; students should be able to evaluate pseudoscientific claims using critical thinking.



Exercises and Critical Thinking

  1. Can you think of a time when you used your intuition to analyze an outcome, only to be surprised later to find that your explanation was completely incorrect? Did this surprise help you understand how intuition may sometimes lead us astray?
  2. Describe the scientific method in a way that someone who knows nothing about science could understand it.
  3. Consider a behaviour that you find to be important and think about its potential causes at different levels of explanation. How do you think psychologists would study this behaviour?
  4. Using the eight processes of critical thinking, evaluate a common proverb or myth, such as “Absence makes the heart grow fonder” or “We only use 10% of our brain.”
  5. Find a claim online for a weight loss pill and use the critical thinking processes to decide if it is an example of pseudoscience.


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Chen, P.-Y., Wang, S.-C., Poland, R. E., & Lin, K.-M. (2009). Biological variations in depression and anxiety between East and West. CNS Neuroscience & Therapeutics, 15(3), 283–294.

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LaBianca, J., & Gibson, B. (2020). Here’s what your handwriting says about you. Reader’s Digest. Retrieved from https://www.rd.com/advice/work-career/handwriting-analysis

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Nisbett, R. E., & Ross, L. (1980). Human inference: Strategies and shortcomings of social judgment. Englewood Cliffs, NJ: Prentice Hall.

Seedat, S., Scott, K. M., Angermeyer, M. C., Berglund, P., Bromet, E. J., Brugha, T. S., & Kessler, R. C. (2009). Cross-national associations between gender and mental disorders in the World Health Organization World Mental Health Surveys. Archives of General Psychiatry, 66(7), 785–795.

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Wells, G. L., & Hasel, L. E. (2008). Eyewitness identification: Issues in common knowledge and generalization. In E. Borgida & S. T. Fiske (Eds.), Beyond common sense: Psychological science in the courtroom (pp. 159–176). Malden, NJ: Blackwell.

Williams, N., Simpson, A. N., Simpson, K., & Nahas, Z. (2009). Relapse rates with long-term antidepressant drug therapy: A meta-analysis. Human Psychopharmacology: Clinical and Experimental, 24(5), 401–408.


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