1.1–1.3: More than just a collection of facts, science is a process for understanding the world.

A walk through Carnarvon National Park, Australia.

You are already a scientist. You may not have realized this yet, but it’s true. Because humans are curious, you have no doubt asked yourself or others questions about how the world works and wondered how you might find the answers.

• Does the radiation released by cell phones cause brain tumors?
• Do large doses of vitamin C reduce the likelihood of getting a cold?

These are important and serious questions. But you’ve probably also pondered some less weighty issues, too.

• Why is morning breath so stinky? And can you do anything to prevent it?
• Why is it easier to remember gossip than physics equations?

And if you really put your mind to the task, you will start to find questions all around you whose answers you might like to know (and some whose answers you’ll learn as you read this book).

• Which parent determines a baby’s sex? Why?
• Why do so few women get into barroom brawls?
• What is “blood doping,” and does it really improve athletic performance?
• Why is it so much easier for an infant to learn a complex language than it is for a college student to learn biology?

Still not convinced you’re a scientist? Here’s something important to know: science doesn’t require advanced degrees or secret knowledge dispensed over years of technical training. It does, however, require an important feature of our species: a big brain, as well as curiosity and a desire to learn. But curiosity, casual observations, and desire can take you only so far.

Explaining how something works or why something happens requires methodical, objective, and rational observations and analysis that are not clouded with emotions or preconceptions. Science is not simply a body of knowledge or a list of facts to be remembered. It is an intellectual activity, encompassing observation, description, experimentation, and explanation of natural phenomena. Put another way, science is a pathway by which we can come to discover and better understand our world.

Later in this chapter, we explore specific ways in which we can most effectively use scientific thinking in our lives. But first let’s look at a single powerful question that underlies scientific thinking:

Once you begin asking this question—of others and of yourself—you are on the road to a better understanding of the world.

The following two stories about popular and successful products show the importance of questioning the truth of many “scientific” claims you see on merchandise packages or read in a newspaper or on the internet.

Dannon yogurt. According to the Federal Trade Commission (FTC), a U.S. government agency with the mission of consumer protection, the Dannon Company claimed in nationwide advertisements that its Activia yogurt relieves irregularity and helps with “slow intestinal transit time.” Dannon also claimed that its DanActive dairy drink helps prevent colds and flu (FIGURE 1-1). The FTC charged that the ads were deceptive because there was no substantiation for the claims and, further, that the claims had been clinically proven to be false. In an agreement finalized in 2011, Dannon agreed to pay $21 million in fines and to stop making those claims unless the company gets reliable scientific evidence demonstrating the claims.

Figure 1.1: Some products claim to improve our health, but how do we know whether they work?

Airborne. For more than 15 years, the product Airborne has been marketed and sold to millions of customers. On the packaging and in advertisements, the makers originally asserted that Airborne tablets could ward off colds and boost your immune system (see Figure 1-1). Not surprisingly, Airborne quickly became a great success; it has generated more than $500 million in revenue. Then some consumers posed a reasonable question to the makers of Airborne: How do you know that it wards off colds?

To support their claims, the makers of Airborne pointed to the results of a “double-blind, placebo-controlled study” conducted by a company specializing in clinical drug trials. We’ll discuss exactly what those terms mean later in the chapter; for now we just need to note that as a result of a class-action lawsuit, it became clear that no such study had been conducted and that there was no evidence to back up Airborne’s claims. The Airborne company removed the claims from the packaging and agreed to refund the purchase price to anyone who had bought Airborne. It also removed any reference to its “clinical trials,” with the company’s CEO saying that people “are really not scientifically minded enough to be able to understand a clinical study.”

Are you insulted by the CEO’s assumption about your intelligence? You should be. Did you or your parents fall for Airborne’s false claims? Possibly. But here’s some more good news: you can learn to be skeptical and suspicious (in a good way) of product claims. You can learn exactly what it means to have scientific proof or evidence for something. And you can learn this by learning what it means to think scientifically.

Scientific thinking is important in the study of a wide variety of topics: it can help you understand economics, psychology, history, and many other subjects. Our focus in this book is biology, the study of living things. Taking a scientific approach, we investigate the facts and ideas in biology that are already known and study the process by which we come to learn new things. As we move through the book, we explore the most important questions in biology.

• What is the chemical and physical basis for life and its maintenance?
• How do organisms use genetic information to build themselves and to reproduce?
• What are the diverse forms that life on earth takes, and how has that diversity arisen?
• How do organisms interact with each other and with their environment?

In this chapter, we explore how to think scientifically and how to use the knowledge we gain to make wise decisions. Although we generally restrict our focus to biology, scientific thinking can be applied to nearly every endeavor, so in this chapter we use a wide range of examples—including some from beyond biology—as we learn how to think scientifically. Although the examples vary greatly, they all convey a message that is key to scientific thinking: it’s okay to be skeptical.

Fortunately, learning to think scientifically is not difficult—and it can be fun, particularly because it is so empowering. Scientific literacy, a general, fact-based understanding of the basics of biology and other sciences, is increasingly important in our lives, and literacy in matters of biology is especially essential.