In a naturalistic experiment, you contrive to collect experimental data under natural conditions. You make the data happen, out in the natural world (not in the lab), and you evaluate the results.
In a memorable experiment, elegant in its simplicity of design, Doob and Gross (1968) had a car stop at a red light and wait for 15 seconds after the light turned green before moving again. In one experimental condition, they used a new car and a well-dressed driver. In another condition, they used an old, beat-up car and a shabbily dressed driver. They repeated the experiment many times and measured the time it took for people in the car behind the experimental car to start honking their horns. It won’t surprise you to learn that people were quicker to vent their frustration at apparently low-status cars and drivers.
Piliavin et al. (1969) did a famous naturalistic experiment to test the ‘‘good Samaritan’’ problem. Students in New York City rode a particular subway train that had a 7.5-minute run at one point. At 70 seconds into the run, a researcher pitched forward and collapsed. The team used four experimental conditions: The ‘‘stricken’’ person was either black or white and was either carrying a cane or a liquor bottle. Observers noted how long it took for people in the subway car to come to the aid of the supposedly stricken person, the total population of the car, whether bystanders were black or white, and so on. You can conjure up the results. There were no surprises.
Harari et al. (1985) recruited drama majors to test whether men on a college campus would come to the aid of a woman being raped. They staged realistic-sounding rape scenes and found that there was a significant difference in the helping reaction of male passersby if those men were alone or in groups.
And Walker (2006) rode his bicycle 200 miles through Bristol and Salisbury, England during regular working hours dressed as an ordinary commuter—sometimes wearing a helmet, sometimes not; sometimes wearing a woman’s long-haired wig, sometimes not. Walker outfitted his bike with a hidden distance sensor and a tiny camera and then, systematically varying his distance from the curb, he measured how close cars came as they passed him. The farther from the edge he rode, the closer drivers came; drivers stayed farther from him when he appeared to be a woman; and drivers came closer to him when he wasn’t wearing a helmet than when he was. Fortunately, both times he got hit doing this experiment, he was wearing the helmet (Further Reading: naturalistic experiments).