Reading and thinking critically about cause-effect essays requires careful analysis and close attention to detail. The overall questions to keep in mind are these. (For more on reading actively, see Chapter 3; for more on thinking critically, see Chapter 4.)

Use the following suggestions when reading text that deals with causes and effects:

Reading and evaluating causal relationships involves close analysis and may require that you do research to verify a writer’s assertions. Use the following questions to think critically about the causal analyses you read.

What is the writer’s purpose? Consider how the writer describes certain causes or effects and how this description advances his or her purpose. For example, it may persuade readers to adopt a particular position on an issue: A detailed description of the physical effects of an experimental drug on laboratory animals may strengthen an argument against the use of animals in medical research.

Does the writer cover all major causes or effects fairly? Consider whether the writer presents a fair description of all major causes or effects. For example, a writer arguing in favor of using animals for medical research might fail to mention the painful effects of testing on laboratory animals. Conversely, a writer who opposes using animals for medical research might fail to mention that several human diseases are now controllable as a result of tests performed on animals. In either case, the writer does not offer a complete, objective, or fair account of the controversy.

Does the writer provide sufficient evidence for the causal relationship? Determine whether the writer provides sufficient supporting evidence to prove the existence of a causal relationship between events or phenomena. For example, suppose a writer makes this assertion: “Medical doctors waste the resources of health insurance companies by ordering unnecessary medical tests.” For support, the writer relies on one example involving a grandparent who was required to undergo twenty-two tests and procedures before being approved for minor outpatient surgery. This anecdote is relevant to the writer’s assertion, but one person’s experience is not enough to prove a causal relationship. Consider whether the writer might have provided additional support (such as statistics and expert opinion) or whether adequate support could not be found for the assertion.

Does the writer avoid common reasoning errors? Stay alert to common errors in reasoning, such as confusing chronology with causation the post hoc, ergo propter hoc (“after this, therefore because of this) fallacy, in which the writer assumes that event A caused event B simply because B followed A. Superstitious thought is often based on this fallacy. (Carrying a rabbit’s foot, for example, does not cause a streak of good luck.) Similarly, a writer may mistake correlation with causation and assume that just because two events occur at about the same time that they are causally related. For example, an increase in sales of both snow shovels and mittens does not mean that snow shoveling causes people to buy more mittens. More likely, a period of cold, snowy weather caused the increased sales of both items. A third type of logical problem occurs when a writer misidentifies causal relationships. For example, consider the relationship between failure in school and personal problems. Does failure in school cause personal problems, or do personal problems cause failure in school? In some cases a third factor, such as an inappropriate classroom environment, may be the cause of both the failure and the problems. Be sure the writer provides evidence that a causal relationship not only exists but also works in the direction the writer thinks it does.