Ask Questions; Be Willing to Wonder What is one kind of question that parents of young children often hear? “Why” questions: “Why is the sky blue, Mommy?” “Why doesn't the plane fall?” “Why don't pigs have wings?” Unfortunately, as children grow up, they tend to stop asking “why” questions. (Why do you think this is?)

“The trigger mechanism for creative thinking is the disposition to be curious, to wonder, to inquire,” observed Vincent Ruggiero (1988). “Asking ‘What's wrong here?’ and/or ‘Why is this the way it is, and how did it come to be that way?’ leads to the identification of problems and challenges.” This educational program isn't working; why not? I want to stop smoking and improve my grades; why can't I seem to do it? Is my way of doing things the best way, or just the most familiar way? Critical thinkers are willing to question received wisdom—“We do it this way because this is the way we have always done things around here”—and ask, in essence, “Oh, yeah? Why?”

In psychological science, knowledge advances by asking questions. What is the biological basis of consciousness? How are memories stored and retrieved? Why do we sleep and dream? What causes schizophrenia? Critical thinkers are not discouraged by the fact that questions like these have not yet been fully answered; they see them as an exciting challenge. And they even enjoy thinking critically about poorly phrased questions, which can lead us to wrong answers. Consider the matter of homework. The questions have usually been: “Are American children doing too much homework or too little?” But as one observer wrote, “The question should be ‘how effectively do children's after-school assignments advance learning?’” (Paul, 2011). As you probably know from experience, spending hours studying won't help you learn if you are not studying effectively—as you will see at the end of this chapter.

Define Your Terms After you have raised a general question, the next step is to frame it in clear and concrete terms. “What makes people happy?” is a fine question for midnight reveries, but it will not lead to answers until you have defined what you mean by “happy.” Do you mean being in a state of euphoria most of the time? Do you mean feeling pleasantly contented with life? Do you mean being free of serious problems or pain?

Vague or poorly defined terms in a question can lead to misleading or incomplete answers, or cause misunderstandings. For example, are people becoming less prejudiced against other groups? The answer may depend in part on how you define “prejudice.” Everyone might agree that a conscious dislike of another group qualifies as a prejudice. But what if a person feels uncomfortable with another group because he or she is unfamiliar with its rules and beliefs; is that person bigoted or just uninformed? What if a person blurts out an insulting remark while drunk; is that person prejudiced or just drunk? What if a person is unaware of having any prejudiced beliefs or feelings, yet a test suggests that he or she has an unconscious prejudice; what does that mean? Psychologists have defined and measured this phenomenon, and they have obtained different results depending on how they define prejudice.

Examine the Evidence Have you ever heard someone in the heat of an argument exclaim, “I just know it's true, no matter what you say”? Have you ever made such a statement yourself? Accepting a claim or conclusion without evidence is a sure sign of lazy thinking. A critical thinker asks, “What evidence supports or refutes this argument and its opposition? How reliable is the evidence?” Have you ever received some dire warning or funny “I swear it's true!” story from a friend, and then posted it on your Facebook page, only to learn later that it was a hoax or an urban legend? A critical thinker would ask, “Is this story something I'd better check out on snopes.com before I tell my closest 90,000 friends?”

Sometimes, of course, checking the reliability of the evidence for a claim is not practical. In those cases, critical thinkers consider whether the evidence comes from a reliable source (Lipps, 2004). Sources who are reliable exercise critical thinking themselves. They have education or experience in the field in which they claim expertise. They do not pressure people to agree with them. They are trusted by other experts in the field. They share their evidence openly. In psychology, they draw on research conducted according to certain rules and procedures For more tips on distinguishing reliable from less-reliable information, watch the video Debunking Myths 2.

Analyze Assumptions and BiasesAssumptions are beliefs that are taken for granted. Critical thinkers try to identify and evaluate the unspoken assumptions on which claims and arguments may rest—in the books they read, the political speeches they hear, and the ads that bombard them daily. The assumption might be “All Democrats (or Republicans) are idiots,” or “You need the product we are selling,” or “People have free will and are entirely responsible for any crimes they commit” (or, conversely, “People's criminal behavior is a result of their biology or horrible childhood, so they aren't responsible for their acts”). Everyone, of course, makes assumptions about how the world works; we could not function otherwise. But if we do not recognize our own assumptions and those of other people, our ability to judge an argument's merits may be impaired.

When an assumption or belief keeps us from considering the evidence fairly, it becomes a bias. A bias often remains hidden until someone challenges our belief and we get defensive and angry. For instance, most people, psychologists included, believe that parents are the most important influence in shaping a child's personality. It's obvious, isn't it? In her book The Nurture Assumption, Judith Rich Harris (2009) dared to question that assumption. Genes and peers, she argued, are more important influences on a child's personality and behavior than how the parents raise the child. Because this idea challenged a widespread bias, it immediately provoked a storm of disbelief, outrage, and scorn. Some critics focused on Harris's lack of credentials instead of her facts or her logic (although she wrote a successful developmental psychology text, she does not have a PhD), and many attacked the book without even bothering to read it. That is the nature of a bias: It creates intellectual blinders.

Avoid Emotional Reasoning Emotion has a place in critical thinking. Passionate commitment to a belief motivates people to think boldly, defend unpopular ideas, and seek evidence for creative new theories. But when gut feelings replace clear thinking, the results can be dangerous. “Persecutions and wars and lynchings,” observed Edward de Bono (1985), “are all a result of gut feeling.”

Because our emotional reactions and cherished beliefs feel so right, so natural, we may not realize that people who hold an opposing viewpoint feel just as strongly as we do. But they usually do, which means that emotional conviction alone cannot settle arguments; in fact, it often makes them worse. The fact that you really, really feel strongly that something is true—or want it to be—doesn't make it so.

All of us are apt to feel threatened and get defensive whenever our most cherished beliefs, or commitment to a course of action, are challenged by empirical evidence (Tavris & Aronson, 2007). At such times, it is especially important to separate the data from emotional reasoning. In a 2011 judicial ruling that vaccines do not cause autism, one of the judges expressed sympathy for parents coping with their children's disorder, but added, “I must decide this case not on sentiment, but by analyzing the evidence.” You probably hold strong feelings about many topics of psychological interest, such as drug use, racism, sexual orientation, the origins of intelligence, and what makes people fat or thin. As you read this book, you may find yourself quarreling with findings that you dislike. Disagreement is fine; it means that you are reading actively and are engaged with the material. All we ask is that you think about why you are disagreeing: Is it because the evidence is unpersuasive or because the results make you feel anxious or annoyed?

Don't Oversimplify Critical thinkers look beyond the obvious, resist easy generalizations, and reject either–or thinking. For instance, is it better to feel you have control over everything that happens to you or to accept with tranquility whatever life serves up? Either position oversimplifies. A sense of control has many important benefits, but sometimes it is best to go with the flow.

A common form of oversimplification is argument by anecdote—generalizing from a personal experience or from a few examples to everyone: One crime committed by a paroled ex-convict means that parole should be abolished; one friend who hates her school means that everybody who goes there hates it. Anecdotes are often the source of stereotyping as well: One dishonest mother on public assistance means everyone on welfare is dishonest; one encounter with an unconventional Californian means they are all flaky. Critical thinkers want more evidence than one or two stories before drawing such sweeping conclusions. Sharpen your critical thinking skills by watching the video Debunking Myths 3.

Consider Other Interpretations Critical thinkers creatively generate as many reasonable explanations of the topic at hand as possible before settling on the most likely one. Suppose a news magazine reports that people with chronic depression are more likely than nondepressed people to develop cancer. Before concluding that depression causes cancer, you would need to consider some other possibilities. Perhaps depressed people are more likely to smoke and to drink excessively, and those unhealthful habits increase their cancer risk. Or perhaps early, as yet undetected cancers produce biochemical changes that create the physical and emotional symptoms of depression. Alternative explanations such as these must be ruled out by further investigation before we can conclude that depression is a direct cause of cancer. (It's not, by the way.)

After several explanations of a phenomenon have been generated, a critical thinker chooses the one that accounts for the most evidence while making the fewest unverified assumptions. This principle is known as Occam's razor, after the 14th-century philosopher who first formulated it. Thus, if a fortune-teller reads your palm and predicts that you will meet the love of your life on a subway in London, that you will make a fortune with an Internet enterprise, and that you will have red-haired twins, then one of two things must be true (Steiner, 1989):

• The fortune-teller can actually sort out the infinite number of interactions among people, animals, events, objects, and circumstances that could affect your life and can know for sure the outcome. Moreover, this fortune-teller is able to alter all the known laws of physics and defy the hundreds of studies showing that no one, under proper procedures for validating psychic predictions, has been able to predict the future for any given individual.

  OR

• The fortune-teller is faking it.

A critical thinker would prefer the second alternative because it requires fewer assumptions and has the most supporting evidence.

Tolerate Uncertainty Ultimately, learning to think critically teaches us one of the hardest lessons of life: how to live with uncertainty. Sometimes there is little or no evidence available to examine. Sometimes the evidence permits only tentative conclusions. Sometimes the evidence seems strong enough to permit conclusions until, exasperatingly, new evidence throws our beliefs into disarray. Critical thinkers are willing to accept this state of uncertainty. They are not afraid to say, “I don't know” or “I'm not sure.” This admission is not an evasion but a spur to further creative inquiry. Critical thinkers know that the more important the question, the less likely it is to have a single simple answer. The need to accept a certain amount of uncertainty does not mean that we must abandon all of the beliefs and convictions that motivate and inspire us. It means only that we must hold them lightly enough to change our minds when we need to.

Critical thinking is a process, not a once-and-for-all accomplishment. No one ever becomes a perfect critical thinker, entirely unaffected by emotional reasoning and wishful thinking. We are all less open-minded than we think; it is always easier to poke holes in another person's argument than to critically examine our own position. Yet we think the journey is well worth the mental effort because the ability to think critically can help people in countless ways, from saving them money to improving their relationships.

As you read this text, keep in mind the eight guidelines we have described, which are summarized in Review1.1. You can get practice applying these critical thinking guidelines by completing the journal writing prompts you’ll find throughout this book.

Review 1.1

Reviewing Critical Thinking Guidelines