What is an example of a controlled setting in psychological research?

A controlled setting in psychological research refers to an environment where variables can be systematically managed and manipulated to observe their effects, thus allowing researchers to establish cause-and-effect relationships. The example of examining the effects of caffeine on reaction times in a lab demonstrates this concept effectively. In a laboratory, conditions such as lighting, temperature, and the timing of caffeine administration can be precisely regulated. This control minimizes the impact of extraneous variables and gives researchers the ability to draw clearer conclusions about the relationship between caffeine consumption and reaction time.

In contrast, the other options involve environments that are less controlled and can introduce multiple uncontrolled variables. For example, studying children in playgrounds involves a dynamic and unpredictable setting where many factors influence children's behavior and interactions. Interviewing participants at their workplaces can yield varying results based on different workplace environments and situations. Surveying people in shopping malls is also subject to biases and external influences that can affect participant responses. Therefore, option B stands out as the only instance that exemplifies a controlled research setting effectively.