Description
This book is called Tools for Critical Thinking in Biology because I use mostly biological examples. Another title might have been Tools for Critical Thinking in Life Illustrated by Biological Examples. I use biological examples because I’m a biologist and know biological stories better than ones from other sciences. Of course critical thinking is used in all areas of scholarship—there might be parallel books called Tools for Critical Thinking in History, or Tools for Critical Thinking in English Literature. In fact, if you are a student of either of these fields, you might try applying some of the general methods illustrated here to questions in history or English literature. In some ways, critical thinking seems closer to the surface in the sciences—physical, biological, and social—than in the humanities. Therefore I hope you find this book useful whatever your primary academic (and other) interests.
Chapter 1 introduces the kinds of questions biologists ask. This may seem pretty elementary, but it actually has important implications. First, these questions are the same as those asked by journalists investigating a story—who, what, when, where, how, and why. Indeed, they are the same questions that we all ask in daily life. Second, and of more importance, these questions fall into two categories—questions about basic facts (who, what, when, and where) and questions about causation (how and why). Both types of questions are important and answering questions about causation depends on getting the basic facts right. Ultimately, however, answering questions about causation gives deeper understanding than answering questions about basic facts. As illustrated in Chapter 1 and several later chapters, understanding causation can be deeply satisfying and have great practical importance. One prerequisite for critical thinking is asking the right questions and knowing how different kinds of questions are related to each other; the main example in Chapter 1 of migration by monarch butterflies illustrates these ideas.
The basic raw material for all discovery in science, as in life itself, is observation. Critical thinking depends on learning how to assess the validity of observations. Is the ivory-billed woodpecker really extinct, or does it still exist in bottomland swamp forests of the southeastern United States? How about wolverines in California? As a more practical example, how should we evaluate eyewitness identifications of alleged perpetrators of crime? Chapter 2 uses these examples to illustrate the challenges of interpreting basic observational evidence, especially in light of our tendency to follow a form of belief preservation called confirmation bias.
All sciences, including biology, are quantitative. While Chapter 2 focuses on using individual observations as evidence, Chapter 3 builds on the fact that much science depends on evaluating multiple observations, that is, data. Therefore I introduce some basic tools for organizing and analyzing data in Chapter 3. These tools include descriptive statistics and graphs. Both of these tools are important for nonscientists to appreciate,partly because they are used commonly in the media, often without explanation. Just as one picture can be worth 1,000 words, graphs are especially important in science and for critical thinking in general, so I use lots of graphs in the book.