The Hawthorne effect refers to the phenomenon in which individuals alter their behavior because they are aware of being observed. This was first identified in studies conducted at the Western Electric Hawthorne Works in the 1920s and 1930s, where workers improved their performance simply because they knew they were being watched.
- The bias in memory recall due to emotional states (B) relates to how emotions can affect memory retrieval, but this is not the Hawthorne effect.
- The resistance to change in group dynamics (C) refers to the tendency of groups to resist change, which is unrelated to the concept of being observed.
- The effect of rewards on intrinsic motivation (D) focuses on how rewards can influence motivation, but it does not describe the effect of observation on performance.
Therefore, the Hawthorne effect is the correct answer.