One thing I have learned in a long life is that all our science, measured against reality, is primitive and childlike—and yet it is the most precious thing we have.

—Albert Einstein

The ad catches your eye, “build confidence, reach peak performance in work, studies, the arts or sports…conquer habits like smoking, alcohol and drugs without the struggle…relieve stress, enhance healing…[achieve] effortless weight control for a lifetime.”1 You read this and think, “Sounds great—how can I do it?” Upon further reading, you learn that a newly discovered technology using subliminal tapes is the answer. The tapes play while you sleep, and since they target your unconscious, proponents claim that dramatic results can be quickly achieved. Too good to be true? Maybe, but the ad appeared in Psychology Today, a reputable magazine whose articles cover current developments in psychological research that influence our everyday life.

Intrigued, you search the Internet and find research reporting that subliminal tapes can enhance a person's memory, self-esteem, concentration, and word power. It seems pretty convincing, so you buy a tape to improve your memory. After playing it for a few weeks while you sleep, you notice that you actually can remember things better. “It's amazing!” you tell your friends, “You've got to try this tape.” But does the improvement you see provide reliable evidence that the tape works? Consider the following study.

Psychologists gave one group of people a subliminal memory tape and told them it was designed to improve their memory. Another group was given a self-esteem tape and told it would improve their self-esteem.2 Prior to each person's listening to the tape, the psychologists measured each individual's perception of his or her memory and self-esteem, and then instructed each to listen to the assigned tape every day for one month. When measured a month later, the people who used the memory tape reported improved memory, while those using the self-esteem tape reported improved self-esteem. Seems pretty convincing, doesn't it? But how good is this evidence? Although it may seem scientific, a close examination reveals that the evidence is purely anecdotal—amounting to nothing more than the personal testimonials of people who have used the tapes.

To scientifically test the credibility of these personal testimonials, the psychologists also analyzed two additional groups of people, but for these groups the tape labels were switched. That is, the “memory” tape was labeled “self-esteem,” and the “self-esteem” tape labeled “memory.” Amazingly, those who thought they had received the memory tape reported improved memory, despite having listened to a self-esteem tape, while the group who believed they were listening to a self-esteem tape reported higher self-esteem. To top it off, other more objective tests of memory effectiveness and self-esteem revealed no actual improvement in any of the groups. So the tapes were worthless, but they generated plenty of personal testimonials. Why? People thought their memory or self-esteem improved because they were expecting improvement. The implications are clear. We simply can't trust personal testimonials to provide us with objective, reliable evidence.

If we can't use personal testimonials to form our beliefs, what can we do? The most credible forms of evidence are those produced by scientific inquiry, and one of the more common and effective techniques used by scientists to evaluate a claim is the experimental method. With an experiment, some people receive a certain treatment (the “experimental” group), while others do not (the “control” group), and the two groups are compared to see if the treatment had any effect.

What about all those studies reported on the Web supporting the usefulness of subliminal tapes? They seemed scientific. The problem is, many studies that appear to be scientific are, in fact, the result of pseudoscience. Remember, those who practice pseudoscience often try to look “scientific,” so it's sometimes difficult to tell the two apart. How can we tell the difference? First, if the study relies heavily on personal testimonials, be wary. Second, if an experiment is conducted, we need to evaluate how tightly the experiment was controlled. Good science requires extremely tight controls, while the controls in pseudoscientific experiments are often loose, opening up the possibility that alternative explanations caused the results. Not all experiments are created equal—an experiment is only as good as the tightness of its controls.

YOU HAVE TO TIGHTEN IT UP

To illustrate the importance of an experiment's controls, let's design a study to investigate whether a new drug is effective in treating a certain illness. We could simply give the drug to a group of people and see if they get better. But we already know that people sometimes get better on their own because the body has a tremendous capacity to heal itself. And, diseases have a natural variability, so even people with major illnesses can feel better at times. If people improve after taking the new drug, we might be tempted to claim that the drug cured the disease, but that's not necessarily the case. This research design doesn't rule out the other competing explanations.

So let's add a second group to the study, people who do not receive the drug treatment. Getting better in this group could only be the result of the body's ability to heal itself or the natural variability of the disease. If about the same number of people get better with and without the treatment, we can conclude that the drug did not contribute to the healing. But what if significantly more people got better in the group who received the drug? Can we conclude that the drug worked? I'm afraid not. We still have plausible alternative explanations. Remember the placebo effect—if people believe they are receiving a treatment that works, even if it's nothing more than a sugar pill, they are more likely to get better than if they receive no pill at all.

We can eliminate this problem by replacing the no treatment group with a placebo group (i.e., people who receive a sugar pill or some other treatment with no medicinal benefits). Further, we have to be sure that the people don't know whether they're receiving the actual drug or the placebo. That is, the participants have to be “blind” to the treatment they receive. Are these controls tight enough? Not yet! Studies have found that if the person giving out the pills knows who gets the drug and who gets the placebo, he can give subtle clues, even unknowingly, that tell participants what they're getting. So both the person giving the pills and the people receiving the pills must be blind to who is receiving what. The experiment is then said to be “double-blind.”

Even with double-blind controls in place, other factors can come into play that may influence the results. What if there were more men in the drug treatment group, and more women in the control group? What if the people in the drug group exercised more or ate more healthy foods? These things could also affect the study's results, and may lead us to believe falsely that the drug had an effect when it didn't. To overcome these problems, we have to randomly assign people to the different groups. By randomly assigning a large number of individuals to the different groups, we should get a similar mix of subjects in each of the groups.

As you can see, if you want good evidence, many different types of controls have to be built into a study. Without adequate controls, the door is open to alternative explanations, and there's no sound basis for choosing one over the other. Since many people don't realize the importance of tight controls, they are prone to accept the results of studies when they shouldn't. This unquestioning attitude leads to beliefs in all types of pseudoscientific phenomenon. Think back to the ESP experiments reported earlier. In those studies, subjects could actually see or feel indentations of the symbols they were trying to identify on the backs of the Zener cards. The controls were very loose, and so alternative explanations abounded. Pseudoscience often gets results to support preconceived beliefs because their studies are not tightly controlled. The bottom line is, if we don't assess the quality of the test, we're more likely to form erroneous beliefs.

And so, the fundamental nature of the experimental method is manipulation and control. A scientist manipulates a variable of interest (e.g., gives a drug to one group and a placebo to another), and sees if there's a difference. At the same time, he/she attempts to control for the potential effects of all other variables (e.g., by randomization). The importance of controlled experiments in identifying the underlying causes of events cannot be overstated. In the real—uncontrolled—world, variables are often correlated. For example, people who take vitamin supplements may have different eating and exercise habits than people who don't take vitamins. As a result, if we want to study the health effects of vitamins, we can't merely observe the real world, since any of these factors (the vitamins, diet, or exercise) may affect health. Rather, we have to create a situation that doesn't actually occur in the real world. That's just what scientific experiments do. They try to separate the naturally occurring relationships in the world by manipulating one specific variable at a time, while holding everything else constant.3 Without such a procedure, we would be doomed to believe in things like therapeutic touch and facilitated communication.

Our knowledge of science and the scientific method is crucial to our ability to form reasoned beliefs. And yet, the National Science Board estimated that two-thirds of us do not clearly understand the scientific process.⁴ The sad truth is that most of us don't know enough about scientific procedures to be able to adequately evaluate the quality of data when we formulate our beliefs.

SO WHAT IS SCIENCE?

Science relies heavily on controlled experimentation, since, as we have just seen, an experiment is one of the best ways to determine if A causes B. Of course, not all of science can use controlled experiments. Many geological and astronomical hypotheses, for example, can't readily be tested in the lab. But they can be tested in the field where we can look for data that confirms or refutes a given hypothesis. So what is science?⁵ The hallmark of science is the rigorous testing of hypotheses. As science writer Kendrick Frazier observes, “Science proposes explanations about the natural world and then puts those hypotheses to repeated tests using experiments, observations, and a creative and diverse array of other methods and strategies.”⁶

My favorite definition of science was proposed by Michael Shermer: “Science is not the affirmation of a set of beliefs, but a process of inquiry aimed at building a testable body of knowledge constantly open to rejection or confirmation.”7 I like this definition because it emphasizes an extremely important point—science does not try to prove any specific belief. Science doesn't start with a preconceived notion of what we should believe, as some other human institutions do. Rather, science is simply the process we use to better understand our world. In fact, a true scientist never claims to know anything with absolute certainty. Instead, a scientist believes that all knowledge is open to rejection or confirmation, and that we are constantly refining and expanding our knowledge of the world. This quest for knowledge may never result in absolute truth—but it's still the best thing we've got to unravel the mysteries of life.

HOW SCIENCE OPERATES

Science generally begins with a simple question about something in our world. For example, does smoking cause health problems? Next, we form a hypothesis to specifically address the question. A hypothesis is a testable statement about the relationship between two or more variables. For our question, a testable hypothesis might be that smoking causes lung cancer. This statement identifies two specific variables that can be measured, smoking and lung cancer, predicts a causal relationship between the variables, and can be falsified. A scientist then conducts an experiment, or uses a number of other rigorous testing methods, to confirm or refute the hypothesis. Upon completion, the study is submitted for publication. But before a study is published, it's reviewed and critiqued by the scientist's peers to ensure that the research is of high-quality. And once in print, the research is open to criticism by the entire scientific community.

This process of review and criticism is one of the most important aspects of the scientific method because it provides an error-correcting mechanism that keeps science on track. In fact, this self-correcting mechanism is a main reason for the success of science over the years.⁸ In science, every idea is open to criticism. When a scientist publishes a study, she must give the details of her study so others can attempt to replicate the results. If the study's results can't be replicated, they're not worth much. As you can see, you have to have pretty thick skin to be a scientist—your work is constantly under scrutiny!

Peer review and criticism are essential because scientists are human, and can make the same decision-making errors as everyone else. Some scientists may have a favorite theory they want to support, and may therefore search for supporting evidence and discount contradictory evidence. The great advantage to the scientific approach, however, is that any scientist's potential biases are scrutinized and criticized by his peers. In essence, science provides a process of checks and balances, where the errors of one scientist are rooted out and corrected by others.9

One study, by itself, can't tell us all that much. Even in legitimate science, the quality of studies can vary, which is one reason we sometimes get conflicting results. Confounding variables can affect the results, statistical errors can be made, and the data can even be faked. That's why others must replicate the findings of any study before we give them much credence.¹⁰ As the preponderance of evidence from different studies converge, our confidence in a finding should rise. For example, initial research on smoking pointed to health problems. However, true experiments are difficult to perform on this issue because you can't force a random sample of people to smoke or stop smoking. As a consequence, researchers had to analyze the incidence of illness in smokers and nonsmokers. But any observed differences in one study could have been the result of some confounding variable. The smokers examined in one study might have been experiencing more stress, and it actually could have been the stress causing their health issues and not smoking. To eliminate this and other possible explanations, a number of studies needed to be conducted to ensure that other competing explanations, such as stress, diet, exercise, age, and gender, were ruled out. As more studies were conducted, the preponderance of the evidence pointed to smoking causing lung cancer and a host of other serious illnesses, so we can have a good deal of confidence in the belief that smoking causes ill effects.

To appreciate the significance of peer review, publication, and replication in the scientific process one just has to look at the cold-fusion fiasco. In the 1980s Professors Stanley Pons and Martin Fleishman of the University of Utah obtained some preliminary results that seemed to indicate they had developed a method to generate unlimited energy through a procedure called cold fusion. Rather than submit their study to a peer-reviewed journal, where their methods could be evaluated, Pons and Fleishman immediately called a press conference to announce their findings. In good science, information is typically not brought to the media until the study has gone through peer review; in fact, if a study hasn't had peer review, it's usually an indication of “bad science”—that is, poorly done science. Pons and Fleishman opted for the immediate fame of a national press conference, but paid the price. After their spectacular announcement, other researchers attempted to replicate their results—and failed. Cold fusion has since been relegated to the junk heap of pseudoscience. The bottom line is, science's greatest strength is its ability to self-correct. Bad science can and will occur, but the process of scientific inquiry should, over time, weed out the bad from the good.

HOW SCIENCE PROGRESSES

Science uses theories in its attempt to better understand our world. Many people believe that a scientific theory is nothing more than a guess or a hunch. But for a scientist, established theories are far more than simple intuition. Viable theories have considerable data in support of their predictions. This distinction between the public's perception of the term and its scientific meaning has led to a lot of misunderstanding. For example, some people say that since evolution is only a theory, we should consider creationism as an equally plausible alternative theory and teach it as such in our schools. This argument demonstrates a fundamental misinterpretation of the word theory. The theory of evolution is not merely someone's guess as to how we got here. Rather, it represents a conceptual structure that is supported by a large and varied set of data. No other alternative approach comes anywhere near to explaining our place in the world than evolution.11 But remember, there are no absolute truths in science. A scientific “fact” is nothing more than a conclusion that has been confirmed to such an extent that it's reasonable to believe it at this time. In science, all knowledge is provisional.¹²

So how does science progress? An initial theory is advanced that attempts to explain part of our world. As we've seen, hypotheses based upon the theory are proposed, and researchers gather data to empirically test them. If the data support the hypotheses, we can be more confident in the correctness of the theory. As the number of studies providing support for the theory increase, it becomes established and accepted by the majority of the scientific community. A well-established theory, such as evolution, is often called a “paradigm,” and has become widely accepted because the evidence from many different scientific studies supports it.13

If, on the other hand, the hypotheses tested are shown to be false, we must modify the theory in some way to adapt to the new evidence, or else discard it and propose a new and better theory. Whether we modify an old theory, or propose a new one, the resulting theory has to explain everything that the old theory did, as well as accommodate the anomalous evidence that has been uncovered. This incremental, adaptive process is how science progresses. Study by study, science brings us closer to a truer understanding of our world.

As an example of scientific progress, consider our early belief that the Earth was flat. A flat Earth theory was accepted because it seemed to make sense—the Earth certainly looked flat! However, some more careful observations were inconsistent with the theory. People noticed, for example, that when a ship sailed away from port, the bottom of the ship disappeared before the top, which couldn't happen if the Earth was flat. So a radical new theory had to be proposed—the Earth was round! As science developed, Sir Isaac Newton's work on gravity predicted that the Earth should not be a perfect sphere. Rather, the Earth should bulge a little at the equator and flatten out at the top and bottom, a fact that was confirmed by empirical tests years later. We now know that the Earth's diameter is 7,900 miles from North to South Pole, and 7,927 miles at the equator. Rather than perfectly round, the Earth is an oblate spheroid.

As this simple example illustrates, theories change or get refined to provide a better understanding of our world. The spherical theory was a significant advancement over the flat Earth theory, while the oblate spheroid theory is an even better refinement. As psychologist Keith Stanovich notes, when scientists argue that all knowledge is tentative, they're typically referring to this process. We're not going to suddenly discover that the Earth is, in fact, a square. But we may further refine our knowledge of the spherical nature of the world. The theory may be altered, but we're getting closer to the true nature of the Earth.¹⁴

Or consider the case of continental drift. Scientists originally thought that land masses on the Earth were stable, but anomalous evidence brought that theory into question. In the early 1900s, meteorologist Alfred Wegener noticed that the west coast of Africa and the east coast of South America appeared to fit neatly together, like pieces of a jigsaw puzzle. In addition, fossils of a freshwater reptile called mesosaurus were found in only two places, Brazil and West Africa, and other dinosaur remains were found separated by the vast Atlantic. Scientists first explained this data by hypothesizing that the dinosaurs must have walked across an ancient, but no longer existing, land bridge. However, as we learned more about our Earth through the study of plate tectonics, we found evidence that the Earth's rigid plates lay atop a layer of hot mantle, which would enable the continents to shift. As the evidence that our landmasses have been moving over time grew, the scientific community shifted paradigms to embrace continental drift. In this way, our knowledge progresses.

So what do we get from science if all its facts are provisional? As we saw in the last chapter, the strength of our beliefs typically follows a continuum, from strong disbelief to strong belief. Where we are on the continuum should be governed by the extent of the valid and reliable evidence in support of a belief, and science provides us with the best way to uncover that evidence. Of course, science sometimes finds conflicting evidence. Remember, individual studies can be flawed or biased (e.g., many studies finding no link between smoking and health risks were purportedly funded by tobacco companies). Since every study will not necessarily reach the same conclusion, we must consider the preponderance of the evidence gathered by scientific researchers if we're to set our beliefs in the most informed manner. In effect, we should ask ourselves if there is general consensus in the scientific community on the issue. If the answer is yes, the most informed belief would be the one that coincides with the consensus view (whether it leads to a stronger belief or disbelief in a certain phenomenon). If, on the other hand, there is no consensus in the scientific research, the most informed position would be to stay at the midpoint of the belief continuum, recognizing that we just don't know.

Can the consensus view be wrong? Of course! But it's still the best evidence we have to base our beliefs upon. And yet, people continue to disregard the findings of science because they don't fit with their own personal or political point of view. For example, when asked about global warming, a well-known conservative preacher indicated that he doesn't believe in it—that it's just a myth!15 It doesn't seem to matter that the vast majority of knowledgeable scientists now believe that substantial evidence exists for the rising of the Earth's temperature. One can only wonder what he was basing his belief upon.

SCIENCE AND THE PUBLIC'S MISPERCEPTIONS

With all that science has offered human civilization over the years, you'd think we would embrace scientific research and findings. In countless ways, science has made our lives immeasurably easier, and has contributed to even extending our life span. However, many people distrust science. Often, people believe that their own intuitive theories of how the world works are quite accurate, and so they question the value and findings of science, especially when it conflicts with their intuition. But our intuitive understanding of things is often wrong. Consider, for example, the research of Michael McCloskey on “intuitive physics.”

Suppose you were twirling a ball tied to the end of a string and the string suddenly snapped. What trajectory would the ball take? When McCloskey asked this question of college students, about one third thought the ball would fly off in a curved arc. But, in fact, it would fly in a straight line. The students' intuition was off the mark.¹⁶ Or consider this: if objects that are moving forward are dropped, such as bombs dropped from a plane, where will they land? About half of the people queried thought the object would fall straight down, indicating a basic misunderstanding of how an object's forward motion determines its trajectory.¹⁷ Now, you may say that these questions are unfair because you'd need a physics course to answer them correctly. But we see falling objects every day, and so we have ample opportunity to observe these phenomena as they naturally occur. Despite considerable personal experience with moving and falling objects, our intuitive theories of motion can be quite inaccurate.¹⁸

McCloskey's findings have a parallel in the social sciences. People often hold intuitive beliefs about human behavior that they think are as good as anything that science has to offer. Essentially, they view the science of psychology as simply a matter of common sense. However, many of our intuitive beliefs about human behavior are wrong.19 As we saw earlier, many people think that religious people are more altruistic than less religious people, that opposites attract, that happy employees are more productive employees, and so on. But when these commonsense notions are carefully studied, they are proven wrong time and time again.²⁰

It's no wonder we think we're excellent judges of human behavior. We have an explanation for nearly everything that happens! For example, many people rely on short, generally accepted, sayings to explain human behavior. These pithy little proverbs also serve to guide our decisions and actions. Unfortunately, for just about every proverb, you can be sure to find another that contradicts it. It's better to be safe than sorry, isn't it? But, on the other hand, nothing ventured nothing gained. Two heads are better than one, but, of course, too many cooks spoil the broth. While a penny saved is a penny earned, it is also true that you can't take it with you. Don't forget to look before you leap, but remember, he who hesitates is lost. Sure, opposites attract, but everyone knows that birds of a feather flock together. It may be true that where there's smoke there's fire, but of course, you can't tell a book by its cover. While we all know that absence makes the heart grow fonder, we also think out of sight, out of mind. If we try, we can find some commonsense saying to explain virtually any behavior, after the fact. As a result, these aphorisms are unfalsifiable, and so they are worthless in explaining behavior or providing sound advice to guide our own behavior.²¹ What's the bottom line? We need scientific inquiry to understand our world.

Some people claim that we can't trust the findings of science because scientists keep changing their minds. First, we're told, “Eggs are bad. Too much cholesterol.” Then we hear, “Eggs are good. They're an important source of protein.” Well, what's the story? Are eggs good or bad? Why can't scientists make up their minds? This view, however, demonstrates a basic misunderstanding of how science operates. As we've seen, science is a cumulative process, and the results of a single study tell us very little. We shouldn't form strong beliefs on the basis of one, or even a small number of studies. When evaluating scientific results, or any other evidence for that matter, we should look at the consensus view of qualified experts. Initial studies may contradict one another, and a number of studies may be needed before a consensus view emerges, but we shouldn't consider initial contradictory findings as a big problem. As Keith Stanovich observed, it's better to view the process like a projector, slowly being brought into focus. The initial blur we see on the screen could be just about anything. As the picture becomes sharper, however, a number of alternative ideas about what the picture is can be ruled out and the contents of the picture become clearer. So it is with the research process. While early contradictory evidence may blur our understanding, later work often brings the picture into sharper focus.22

When programs to help disadvantaged children, such as Head Start, were first studied, we saw headlines like “Early Intervention Raises IQs by Thirty Points,” along with “Head Start a Failure.”²³ What are we to believe from such contradictory headlines? The problem is that the headlines were premature. While they appeared to be definitive, it actually took another decade of research to give us a scientific consensus. As it turns out, while short programs of early intervention do not typically result in thirty-point IQ gains, they do have definite beneficial effects. Children who participated in Head Start were less likely to go into special education classes or to be held back a grade, and they showed improvement in later educational work.²⁴

In effect, the reporting practices of the media can exacerbate the public's mistrust of science. The media typically reports the results of a single study, making it seem as if it's the consensus view. If a later study contradicts the first, we naturally tend to question what science tells us. However, the fault lies not with the science, but with the reporting and our interpretation of those reports. While scientists are noted for being conservative in interpreting a study's findings, the media and the public tend to exaggerate the implications of the results. For example, after initial research found that listening to Mozart marginally improved students' scores on one type of test, and for only a short period of time, the media played up the benefits of classical music. Before long, conscientious moms were playing Mozart symphonies to their unborn babies.

Scientists also seem to disagree on many issues because the science they currently conduct operates on the frontiers of what we know. There are obviously many things that scientists agree upon, things that are so well established from past science that they are accepted as fact. We know that the Earth revolves around the sun and that blood circulates through our bodies. Quite naturally, scientists are interested in other issues—they want to discover the unknown. Since this is where uncertainty lies, consensus is more difficult to come by. But this is also the work that will advance our knowledge.

DIFFERENCE BETWEEN SCIENCE AND PSEUDOSCIENCE

Now that we've examined what science and pseudoscience do, let's recap their differences. Science differs from pseudoscience in the evidence required before a belief is accepted, as well as in the plausibility of its arguments, the testability of its hypotheses, the amount of skepticism and criticism employed, and the benefits it has provided to us.25

UFO researchers claim that scientists are too closed-minded to believe in alien encounters. But are they? In fact, astronomers are extremely interested in finding what's “out there.” They have built elaborate telescopes like the Hubble, sent out space probes, and listened for signs of intelligent life. In fact, the Search for Extraterrestrial Intelligence (SETI) project has been listening for radio signals from space for many years. This endeavor is science because it attempts to find hard evidence for the existence of alien civilizations. Given the immense size of the universe, it's certainly plausible that other life-forms exist somewhere in the cosmos. On the other hand, to believe that aliens are abducting individuals on this planet is to fall prey to pseudoscience. The physical evidence in support of this claim is suspect, and it's highly implausible that aliens are beaming thousands of individuals into spaceships hovering above the Earth, without detection and without anyone being reported missing. A fundamental difference between the two approaches is that science doesn't accept the existence of aliens without hard evidence. Pseudoscience does.

In science, testable hypotheses are developed so that they can be disproved. In pseudoscience, the hypotheses advanced are often not questioned even in the face of negative evidence. For example, when psychics and mediums are put in controlled situations, they fail to demonstrate any facet of extrasensory perception, beyond what you would expect from chance. Instead of accepting these results as evidence against the existence of psi phenomenon, psychics explain them away by claiming that the skeptical investigators conducting the experiments give off “negative energy,” preventing them from performing better. In effect, the psychics set up a situation where they can't be tested. For every test conducted, they provide a reason why it won't work. But, as we saw, if a claim can't be tested, it's worthless.

Skepticism, a cornerstone of science, is suppressed in pseudoscience. Scientists open themselves up for criticism, while pseudoscientists are defensive and wary of opposing views. In pseudoscience, we don't see other pseudoscientists criticizing the results of a study. Why? They all want to believe the same thing. Their agenda is different than that of science. Pseudoscientists already know what they want to believe as they come into a study, and they selectively search for data to confirm their preconceived belief. Of course, science is guided by theories that may bias its search for knowledge. Also, scientists are human, so they can fall prey to human frailties. They have egos and may also want to find support for their pet theory. Fortunately, science has that built in error-correcting mechanism—criticism—to counteract the problems of human frailty. For every scientist publishing the results of a research study, a number of other scientists stand ready to find fault with the research. The end result is that useful ideas are retained, and nonuseful ideas abandoned.26

To appreciate the difference between real science and pseudoscience, just think about the great advancements of our civilization. We live longer, healthier, easier, and, for the most part, more fulfilling lives, primarily due to the knowledge we gained from science. Science has given us cures for a multitude of diseases, the ability to explore space, and technological marvels like the computer, television, and cell phones. On the other hand, paranormal investigators are still trying to establish the basic premise that ESP exists, and it's difficult to find a single practical benefit from that questionable research.²⁷ In the words of magician Penn Jillette, of Penn and Teller fame, “Being pro science is one of the oddest things you can do in show business. Which is very strange, because it was science that, oh, cured polio. I could list others—isn't that enough? Oh, Western medicine doesn't work; I'm sorry, we cured polio…. And guess what? It cures polio even if you don't believe in it.”²⁸ Enough said!

THINKING LIKE A SCIENTIST

So what can we take away from our knowledge of science that would help us set more informed beliefs and make better decisions? Table 3 summarizes the major characteristics of a scientific approach to acquiring knowledge. Each of these items can be extremely useful in our everyday lives. As we've seen, we should keep an open mind to new phenomenon and explanations, but we should also be skeptical of any claim that's unsubstantiated. We have to make sure a claim or belief can be put to the test, because if it can't be tested, we'll never be able to determine its truth or falsehood.

	Table 3
	Characteristics of Thinking Like a Scientist
(1)	Keep an open mind, but be skeptical of any unsubstantiated claim.
(2)	Make sure a claim or belief can be tested.
(3)	Evaluate the quality of the evidence for a belief (e.g., assess the tightness of the controls and don't rely on anecdotal evidence).
(4)	Try to falsify a claim or belief (e.g., look for disconfirming evidence).
(5)	Consider alternative explanations.
(6)	Other things being equal, choose the claim or belief that is the simplest explanation for the phenomenon (i.e., the one that has the fewest assumptions).
(7)	Other things being equal, choose the claim or belief that doesn't conflict with well-established knowledge.
(8)	Proportion your belief to the amount of evidence for or against that belief.

It's extremely important to evaluate the quality of the evidence when testing any claim. We all too often simply accept anecdotal data or trust the results of a research study without evaluating the tightness of the controls. Given our underlying tendency to seek out confirming evidence, we need to be particularly vigilant in our search for disconfirming data. At the same time, we have to consider alternative explanations that may better account for the phenomenon. And, if the alternatives are equally proficient in explaining the phenomenon, we should choose the one that provides the simplest explanation and doesn't conflict with other well-established knowledge.

Finally, we have to proportion our belief to the amount of evidence for or against that belief. If the evidence doesn't strongly support a belief, a leap of faith will never establish the belief as true. We simply can't make something true just by believing it.29 Consequently, we may have to withhold judgment on certain issues until the preponderance of the evidence indicates that it's more prudent to accept one belief over the alternatives. If we follow these basic guidelines used in science, we can all form more reasoned beliefs and make better decisions.