Living well requires that we be able to evaluate our environment rationally. Simple things, like crossing the street, shopping, eating, and listening to our doctors, involve three skills: critical thinking, evidential reasoning, and judging authority. Many people, including previous authors writing for the Skeptical Inquirer (Lett 1990; Wade and Tavris 1990), have discussed the first two of these. Here I focus on the last of them, judging authority, but I must revisit the other two first because they are central to it. These same skills are fundamental to scientific reasoning as well, since the ordinary person and the scientist both need to understand our personal or scientific surroundings. Indeed this short article is an outgrowth of material I present to science students first learning the methods of science, but this should not discourage the nonscience reader, for science and everyday life are far closer in function than most would suppose.

There may be little here not fairly obvious to those of you long involved in issues of science and skepticism, but perhaps it can be of some use in your dealings with students, friends, colleagues, and the wider public.

Critical Thinking

Critical thinking involves eight skills. These skills require that you understand the problem clearly, consider all possible views about the problem, set emotion aside, and be willing to be flexible when solutions are imperfect. The skills will aid you in dealing with the problem.

Table 1. Skills involved in critical thinking (Wade and Tavris 1990) and simple techniques for achieving them.

The first three critical skills in table 1 may be self-evident, but the others are often difficult for people to practice because of human nature. The analysis of assumptions and biases requires a certain amount of personal insight. We all have biases based on our past experiences and personal beliefs, but we must try to set them aside when we need to understand the way the world works. This is often very difficult to do, because we are not even aware of many of our personal biases. One way to identify bias is to make a list of your feelings and knowledge about the subject. Then apply the evidence. If it does not support your feeling, perhaps the feeling is unjustified. Later, after examining other factors, you can return to this issue with a better understanding of your own emotional biases. If in conflict, your feelings should probably be suppressed in favor of evidence.

The last three items are particularly difficult. We all need explanations, and we tend to jump to conclusions based on too little evidence. Again, an analysis of the evidence is required to determine if it is sufficient. Alternative interpretations should always be sought, even if the evidence seems compelling. In science, this process is known as the “method of multiple working hypotheses,” an especially powerful way of approaching the truth (Chamberlain 1897; Platt 1964; Lipps 1999). Does the evidence allow for other possible interpretations? Try to think of other ways to account for the observation or phenomenon you are interested in.

And last, tolerate uncertainty. No one likes uncertainty in our lives-we all want, perhaps need, to know things such as what is before us, why things happen to us, and what happens when we die. Although difficult, tolerating uncertainty can be done by simply setting aside the uncertainties and, for the moment at least, accepting them and moving forward.

Evidential Reasoning

Evidential reasoning should be used in our daily lives, as it is in science, to evaluate various problems and claims that confront us. We might even make such claims ourselves. All claims should, ideally, be subjected to an analysis like that outlined in table 2.

Table 2. Rules for evidential reasoning (Lett 1990), or a guide to intelligent living and the scientific method (Lipps 1999). All claims whether scientific or not, should be subjected to these rules in order to ensure that all possibilities are considered fairly.

Of these points, perhaps the most critical is the last one. Any claim must be sufficient. In other words, you do not have to prove that the claim is false in order to test it; the claimant must provide sufficient proof himself. Second, the more extraordinary a claim, the more extraordinary the evidence must be to test it. For example, if a person claims that some herb has cured his cancer, you would be well advised to seek a good deal of further supporting evidence before risking your own life. Or if a person claims to have an extraterrestrial being in her garage, do not accept a photograph as proof-demand a piece of it for further study. And last, the word of someone is never sufficient to establish the truth of a claim. This article addresses this last issue, judging whether or not that authority is worth considering.

Judging Authority

The evaluation of authority requires special consideration because all of us must depend on authorities for information almost daily. In science too, we scientists rely on other scientists for certain kinds of information or data, simply because we cannot know enough about everything. Scientific papers are scattered through with references to the work of others. The evaluation of those works and their authors are part and parcel of science. It should be so in general life too.

Who can we trust to help us in our daily lives? That question is not easy to answer. A scientist dealing with auto insurance may be as susceptible to pseudo-authority in that area as anyone else. A politician listening to a case for particular legislation may be incapable of judging the claimant, and thus vote incorrectly. A housewife may listen to glamorous stars pitching a particular useless household product on television, and buy it. Everyone is vulnerable to incorrect judgment of authority.

I present some general guidelines for judging authority, but each case may differ and so require additional methods. These additional techniques usually take the form of further probing questions. We all judge authority but sometimes in the emotions or heat of the moment, we forget to question authority. If the authority cannot pass the general guidelines below, don't believe him (or her). Of course, these are not the only ways a person needs to judge authority, for the skilled charlatan will find ways around any such guidelines. Be alert.

1. Most important, does the authority use the skills of critical thinking and evidential reasoning listed in tables 1 and 2? If not, question him using those very skills yourself, and don't believe him until he produces the evidence required.
2. Does the authority have proper credentials? Considerable study or experience in a subject along with the appropriate learning tools are required to become an expert in any field. Does the authority have degrees from a recognized college or university that has the faculty, libraries, and other facilities for proper education in the subject? Has the authority worked in the field for some time for an organization that is known for and equipped for competent dealings in the field?
3. Does the authority have proper affiliations? Is she identified closely with a reliable organization, such as a university, museum, government agency, hospital, or corporation that practices the subject? If not, ask how she makes a living.
4. Does that organization have a stake in the claims made by the claimant? Be suspicious of anyone making claims that support the position or product of their own organization. Seek independent evidence that the claim is correct. This may be hard to do for even relatively common decisions we face, but in its essence, this is simply “comparative shopping.” A good comparative shopper is interested not merely in relative costs, but also in the range of products or services available, the quality of the products or magnitude of the services, warranties, and service contracts. Does the expert provide this information, or does he pressure you to decide before you are ready? Be careful of those who will not allow you the time for a carefully reasoned decision.
5. Has the authority subjected his or her work to peer review? In other words, have other experts evaluated the work so that some independent assessment has been made positively? If not, seek that evaluation yourself or find another authority. In our day-to-day dealings, such information is available on the Internet, Better Business Bureaus, and consumer affairs magazines and agencies.
6. Is the authority a demonstrated expert in the relevant field? Other trustworthy people should rely on this person’s expertise. Do other experts cite their conclusions? If not, find another authority who others do rely on. Do people you know who have used this person’s expertise recommend him?
7. Does the authority present arguments without undue call on unsupported or untenable claims? Does the authority present sufficient evidence to evaluate? If not, find an authority that can provide evidence supporting the claims.
8. Does the authority have a past record of making rational claims backed by evidence or not? Check the usual business sources and your friends.

Even when an authority passes these tests, be aware of lapses that may reveal the degree of knowledge possessed by an expert. Well-known or highly honored people are commonly asked to comment on subjects outside their own field of expertise. We are plagued by testimonials provided by actors, sports figures, television personalities, and a host of others, but do they possess any particular knowledge that would make them an authority on what they are pitching? Probably not. These people should be subjected to exactly the same questions as an unknown authority to determine how much you should rely on their statements. Does a Nobel Prize winner in physics, for example, have any credibility when making pronouncements about evolution? It seems unlikely because the evidence and hypotheses about evolution are very far removed from the usual literature and knowledge base of physics. Be suspicious. Question authority. Use critical thinking and evidential reasoning.

In our daily lives, pseudo-authorities are always making one claim or another to sell you something. Ask questions of your insurance salesman, your plumber, your doctor, your housekeeper, or anyone else that you may depend on for important or essential services and products. Proper judgment of authority can save you money and perhaps a good deal of grief too.

So critical thinking, evidential reasoning, and judging authority are essential to living an intelligent, full, happy, and good life. These are worth considering carefully in our daily lives!

References

• Chamberlain, T.C. 1897. The method of multiple working hypotheses. Journal of Geology 6: 837-848.
• Lett, J. 1990. A field guide to critical thinking. Skeptical Inquirer 14(2) Winter: 153-160.
• Lipps, J.H. 1999. This is science! In Scotchmoor, J., and Springer D.A., (Eds.), Evolution: Investigating the Evidence. Paleontology Society Special Publication 9: 3-16.
• Platt, J.R. 1964. Strong Inference. Science 146(3642): 347-353.
• Wade, C., and C. Tavris. 1990. Thinking creatively and critically. Skeptical Inquirer (14)4, Summer: 372-377.

I want to focus on one reason why the graduates here are unique and special, and suggest a way that they might change the world. Your graduate has joined a tiny percentage of Americans who are scientifically literate. He or she has become part of that 2-3 percent of Americans who understand the process of science-how it works, how science is done and applied. Fewer than 10 million other adults in the U.S. know that. In fact, more than 197 million have little idea how science works at all. In just twenty years, those numbers will rise to 240 million illiterate and only 12.6 million literate in science. Worldwide, that will be over 5 billion, 400 million scientifically illiterate and a mere 285 million scientifically literate people, more or less, in the year 2020.

So what? Is it important that people be scientifically literate? You bet! The late Carl Sagan said it well in his 1996 book The Demon-Haunted World: Science as a Candle in the Dark. In that book, Carl said:

We've arranged a global civilization in which most critical elements profoundly depend on science and technology. We have also arranged things so that almost no one understands science and technology. This is a prescription for disaster.

Let me show you why. Americans are woefully inadequate both in their understanding of how science works and in their knowledge of basic scientific facts. The National Research Council (NRC) questioned a random sample of Americans with ten science questions. Let’s see how you do on that same quiz. This will be your last quiz. I’ll let you keep your own score, and I’ll give you only eight of the questions.

1. How long does it take Earth to go around the Sun? One day, week, month or year? Forty-seven percent knew it took a year. The other choices, however, did not add up to 100%, because some people (15 percent) thought that no answer was correct, because the Sun goes around the Earth!
2. The oxygen we breath comes from plants. Eighty-five percent agreed, and it’s right, and I have no idea how they knew that one.
3. All radioactivity is man-made. Seventy-two percent agreed but you know that’s wrong.
4. Humans lived with dinosaurs, and I don’t mean birds, I mean T. rex. Forty-eight percent of Americans agreed, and every single one of you graduates know it is wrong. Interestingly, that percentage is identical to what newspaper editors believe! And they control our news.
5. Cigarette smoking causes cancer Ninety-one percent agreed, and it is true, yet 30 percent still smoke! Why is this question answered so positively? Because it is an issue that has been in the press and on TV for years. Advertising works!
6. 6. Earth’s core is very hot. Seventy-eight percent agreed. As a geologist, I was especially happy about this, because I thought we must be doing a good job teaching about plate tectonics, convection, and Earth structure. I said so at a talk on this same literacy topic at UCLA to over 1,000 people. At the end, someone stood up and said, “Jere, you are so naive-the reason that so many people agree with that is because that is where they think Hell is!”

There were two short answer questions:

1. What is DNA? Almost any definition was acceptable. The NRC would accept answers like “the blueprint for life,” but only one out of five Americans were even that close. Every one of our graduates knows a much better answer for that question.
2. What is a molecule? Only nine percent could come even close to the right answer. I thought we learned that kind of stuff in grammar or high school!

So the scientific knowledge of our population is pathetic. Here we are, critically dependent in our daily lives on science, yet hardly anyone knows how it works. I'd point out that in the U.S. Congress, the rate is probably even lower. After all, most of them are lawyers. This general condition may well be at the root of numerous problems in the world.

Perhaps this illiteracy is the reason that so many people believe in paranormal and pseudoscientific claims, at their peril. For example, 60 percent of Americans believe that alien spacecraft visit Earth, and a large subset of those people believe the aliens are conducting sexual experiments on people or abducting them. While that is silly, why do we spend $29 billion per year on standard medicine and another almost equal amount ($27 billion) on alternative medicines that cannot be demonstrated scientifically to be effective? Why do people pay outrageous sums of money for weird solutions to their problems? Because they do not understand some very basic ways of dealing with the real world.

Let me give you an example of how it can work. Stephen Jay Gould, who all you graduating students know is a famous paleontologist and evolutionary biologist, was diagnosed with a severe kind of stomach cancer. He wrote about his experience, and I'd like to share just a little of that. He was shocked to learn that he had only eight months to live, or so it seemed initially. But he did not rush off for strange treatments across the border, rely solely on “positive thinking,” nor did he eat raw herbs from the forest. Instead, he realized that eight months is a median, and that he might well die at some time down the line other than eight months. He went to the Harvard Medical School Library and discovered that some people died in a matter of days, but that others lived for decades after diagnosis, for a median meant that half the people with the disease lived between 0 and 8 months and the other half lived longer than that. A few, he realized, must have lived quite long lives. He was determined to move himself into that group. He found out what those people did to live long-what therapies they took, what kinds of doctors they saw, what operations they had, and what kind of lives they led. He did all those things himself and entered into an experimental therapy that might increase the lifespan of victims. He is still alive almost two decades after his diagnosis, and fully expects to live to a ripe old age.

Let’s look at one of the issues in today’s newspapers: Violence in the media. We actually have scientific studies that show people are excited by such programs, but that only much less than 1 percent of the viewers might act violently as a result. But if that number is only 1 out of 100,000, that still means that we could have some 2,000 acts of violence as a result of a media event. Society needs to decide what level of violence it can tolerate, after it understands scientifically how and why fantasy violence in the media may promote actual violence.

And what about this or what about that scientific issue? There are many-deforestation, overfishing, gun distribution, pesticides, earthquake prediction, drug addiction, and many, many more facing us. Who can understand this stuff? Your graduates can, for the most part, because they belong to that very elite group of scientifically literate people.

Why aren’t more people literate and interested in science? After all, we spend somewhere near $3 billion per year in K-12 science education across this nation alone. To produce what? A population that is 98 percent scientifically illiterate. As Carl Sagan, Paul Ehrlich, and some of us up here have said, that is simply not good enough.

At some point people lose interest in science, and all of that money goes down the drain. While there are many reasons, the media is an obvious culprit. Look at the huge number of pseudoscientific programs on television, presented as documentaries, news, dramas, and sitcoms. One network recently showed the particularly antiscientific programs “Mysterious Origins of Man” and “Aliens Among Us,” and other such programs. Their alien program was presented as if it were a true scientific investigation, but it was not the news division that produced it, it was the entertainment division! Thus, truth is confused with fiction, reality with fantasy, and authorities with charlatans. And few people can tell the difference because they simply do not have the tools to do it.

Even the newspapers don’t get it right. Let me give you an example from my own experience. Some time ago, the National Science Foundation (NSF) decided to drill a hole through the Ross Ice Shelf in Antarctica to see what was under it. The Shelf is as big as Texas and may well be an important source of deep ocean water that could affect our climates. Half a dozen engineers and twelve scientists went to the drill site. But the engineers got the drill frozen three-quarters of the way through the ice and no one was able to sample at all. In spite of that, I was able to get some wetsuits down there in time to divert my team to do some exploration diving in McMurdo Sound. There we found a new kind of single-celled organism. The NSF, in its wisdom, decided to have a symposium about the results of the Ross Ice Shelf Project. Investigator after investigator stood up and said they had no results because the engineers got the drill stuck. But I stood up and told them about how we diverted and found a new species of protozoan. Big deal!

Two weeks later, the NSF public relations director called me up and said “I hear you discovered a new species of animal in Antarctica.” I said: “Well, it wasn’t an animal, it was a single-celled protozoan, and besides scientists find new species every day. It is not newsworthy.” He asked: “Is it good to eat?” I said “It’s a single cell-no one in their right mind would even think of eating one!” He continued: “Well, if you did eat it, what would it taste like?” Wearily, I said it had a shell made of sand, and so I suppose it would taste like sand. But, I warned, no one would ever want to eat one. His report went out over Reuters International, and a friend in Rhode Island sent me the clip from his local newspaper with his comment, “Did you really say this, Jere?” It said: “Professor Jere Lipps of the University of California found a new species of animal in Antarctica that is not good to eat because it tastes like sand!”

Be careful with the media, graduates! It’s usually a far cry from the way things really are, especially on TV. Be a skeptical reader and be a skeptical viewer!

The general public sees science as difficult, boring, and often useless. But let me show you a different view. Our graduates know this already.

All of you graduating students probably had Professor David Wake in class. What an enthusiast! I remember when I went in the field with him years ago on the north coast, and he yelled “Stop the van and follow me!” We ran fast to keep up, and I saw him fling himself down next to a rotten log, stick his arm under it, and pull out a yellow and black salamander. Boy, was he excited! He told us all about it-where it lived, what it ate, how it reproduced and why it was important. I gotta say, I didn’t quite get it, but I sure was impressed with his enthusiasm and love for that little salamander.

And our Chairman, Roy Caldwell-I've seen him standing in water up to his rear end down at Berkeley’s lab in Tahiti, smashing rocks all day long to find stomatopods. Those are a kind of snapping shrimp. After a week, he had ten or twelve that he watched for hours in the aquaria. Again, I didn’t exactly get it, but he sure was having fun! And Professor Marian Diamond rushed into my office once and proclaimed “You are so right-brained, Jere!” I really didn’t get that one (and I hope it’s a good thing), but I had seen her explaining her brain research with such enthusiasm and excitement so many times, that I just knew she had just had some wonderful insight while on her way downstairs, and she had to apply it right away to my very own brain.

Professor Tyrone Hayes, together with undergraduates and graduates, gets so excited about frog physiology and endocrinology, I've seen him barely able to talk. And he has so much fun with all of it. I could go on with all of them up here. And I know that while my colleagues may not exactly get why I go wandering off in the desert surrounded by cholla cactus to search in total happiness for fossilized microbes a billion years old that I can’t even see, they do indeed understand the excitement and contentment that I feel. Especially when I think I got it right!

These graduating students feel that too, or will when they find their niche. I've already seen it happen with those undergrads who've taken the IB 158 Moorea class. Those students walk differently when they come back from nine weeks in Tahiti. They started like puppy dogs, but ended up as apprentice scientists that had accomplished something. They thought they were going to paradise, but they ended up in a taro patch, under a bungalow, chasing down geckos through the coconut palms, or dissecting big, ugly parasites from fish caught far at sea. They discovered hard work, no sleep, mosquitoes galore, rats, getting up at 4 a.m. to catch the tide or the ferry to the next island so they could spend the day wading through stinking mangrove swamps, and then staying up until 2 a.m. to do a plankton tow in the rain. And helping each other do those things too. And they loved it! They come away from their science, not just with fading memories of a good time, but with a new life! They know the joy of discovery, the excitement of swimming with whales to observe their behavior, the thrill of solving a difficult problem, and the contentment of knowing they did it right and, especially, that they did it themselves.

You all know that scientists are really no different from other people-they have the full range of emotions: love, hate, envy, and some are the most honest people while others are deceitful. They are normal. But in one respect, scientists are different. Almost all of them really love their work. Contrast that with the 80 percent of Americans who hate their jobs!

Science is fun; science is creative; science is so satisfying. It’s a good life.

Scientific literacy provides far more than knowledge and a way to view the world. It provides enjoyment of life as well. So what is scientific literacy? It is basically three things mixed with an assortment of facts: It is critical thinking, evidential reasoning, and evaluation of authority plus whatever scientific facts you think are particularly important.

Critical thinking involves eight skills, the most important of which are to avoid emotional thinking, determine biases and assumptions, consider other interpretations, and, perhaps, the most important, tolerate uncertainty.

Evidential reasoning includes six rules. Any claim must be falsifiable in theory, the argument must be logical, it must be comprehensive, honest, and the evidence must be replicable. Most importantly here, it must be sufficient. In other words, extraordinary claims demand extraordinary evidence. Don't be fooled by the person who claims to have an alien in his garage when he shows you a blurry picture. Demand that he show you an arm, leg, head, or DNA from his alien, if it has any. Similarly, demand evidence from your doctor, auto repairman, insurance man, Realtor, teacher or whoever, that their claims are underpinned by sufficient evidence to support their claims.

Lastly, question authorities. Do the authorities practice critical thinking and evidential reasoning? If not, don’t believe them. Do they have the proper credentials? If not, don’t believe them. Do they have appropriate employment? If not, question them.

If you do these things, your lives will be happier, just like the people up here and the students down there, and your checkbook will be fuller. You will vote more wisely, you will decide more sensibly about your own lives, and you will live more comfortably with your surroundings. And especially, you will likely get and keep excellent jobs that you actually enjoy. Our graduates have a significant advantage over most other Americans because they are scientifically literate.

And I hope that at least a few of you graduates will take my words here to heart and think hard about how to improve scientific literacy in America. You have the tools to change our world, just like other past Berkeley graduates. Our nation deserves it, and you deserve it. Do not let Carl Sagan’s “prescription for disaster” come true! Change the world. You can do it.

References

• Ehrlich, P.R., and Ehrlich, A.H. 1996. Betrayal of Science and Reason: How Anti-Environmental Rhetoric Threatens Our Future. (Washington, D.C., Island Press).
• Eve, R.A., and Harrold, F.B. 1991. The Creationist Movement in Modern America. (Boston, Twayne Publishers).
• Gould, Stephen Jay. 1996. Full House. (New York, Harmony Books)
• Lederman, L.M. 1996. A strategy for saving science. Skeptical Inquirer 20: 23-28.
• Lett, J. 1990. A field guide to critical thinking. Skeptical Inquirer 14: 153-160.
• Lipps, J.H. 1999. Beyond Reason: Science in the Mass Media, p. 71-90, in J.W. Schopf (Ed.), Evolution! Facts and Fallacies. Academic Press, San Diego.
• Limbaugh, R. 1992. The Way Things Ought to Be. (New York, Pocket Books).
• Limbaugh, R. 1992. See I Told You So. (New York, Pocket Books).
• Marrs, J. 1997. Alien Agenda. (New York, HarperCollins Publishers).
• Miller, J.D. 1987. The scientifically illiterate. American Demographics 9:26-31.
• National Science Board. 1996a. Science and Engineering Indicators-1996. NSB 96-21. (Washington, D.C.: U.S. Government Printing Office. http://www.nsf.gov/sbe/srs/seind96/start.htm).
• National Science Board. 1996b. US Science and Engineering in a Changing World. NSB 96. (Washington, D.C.: U.S. Government Printing Office. http://www.nsf.gov/sbe/srs/seind96/start.htm).
• Perkins, R., Jr. 1995. Logic and Mr. Limbaugh. (Chicago, Open Court).
• Sagan, C. 1996. The Demon-Haunted World. (New York, NY: Random House).
• Shermer, M. 1997. Why People Believe Weird Things. (New York, NY: W. H. Freeman and Co.).
• Wade, C., and Tavris, C. 1990. Thinking critically and creatively. Skeptical Inquirer 14: 372-377.