Here are four words that make many people nervous: research,statistics,methods, and math. “What do we have to learn this stuff for?” our students have often lamented. “I'm never going to need it anyway. Let's just cut straight to the findings.” In this chapter, we hope to persuade you that of all the stuff you are going to learn in psychology, the information in this chapter may be the most important for protecting yourself from making wrong choices, adopting mistaken beliefs, or coming to wrong conclusions. Consider these claims:

• A study reports that testosterone, that famously male hormone, plummets after a man becomes a parent. And the more time he spends caring for his children, the lower his testosterone drops. Do men have to choose between manliness and dadliness?

• Various studies report that playing fast-paced video games such as Medal of Honor and Grand Theft Auto improves players' cognitive abilities, such as visual attention and speed of response. Moreover, these games have a “transfer effect,” improving visual skills in other areas of life. Does this mean that college students now have a legitimate reason to spend more time playing video games?

• A paper in a major psychology journal claims that the results of nine experiments, involving 1,000 college students, found “statistically significant” evidence of extrasensory perception (ESP). The students had to choose which of two curtains on a computer screen had an erotic picture behind it, and they allegedly demonstrated ESP by doing this at a rate that was slightly above chance (Bem, 2011). Stephen Colbert had a lot of fun with this study, as you can imagine. But was it good evidence of ESP?

• Your 9-year-old brother is autistic. He lives in his own private world, cut off from normal social interaction. He does not speak, and he rarely looks you in the eye. He has never been able to function in a public school classroom. You hear about a technique called “facilitated communication” (FC), in which children with autism are placed in front of a keyboard while an adult “facilitator” gently places a hand over the child's hand or forearm. The method's proponents claim that children who have never used words before are able to peck out complete sentences, answer questions, and divulge their thoughts. Some children, through their facilitators, have supposedly mastered advanced subjects or have written poetry of astonishing beauty. Should your brother receive FC?

By the time you finish this chapter, you will know how to think about these questions and the many others you encounter. Research methods are the tools of the psychological scientist's trade, and understanding them is crucial for everyone who reads or hears about a new program or an “exciting finding” that is said to be based on psychological research. Trying to practice critical thinking or apply psychological findings to your own life without having these tools is like trying to dig a foundation for your house with teaspoons. You could do it, but it will take a long time and the result won't be very sturdy. Knowing the difference between claims based on good research and those based on sloppy research or anecdotes can help you make wiser psychological and medical decisions, prevent you from spending money on worthless programs, and sometimes even save lives.