Which of the following can be a consequence of investigator effects?

Choosing "unwanted influence on the dependent variable" captures the essence of what investigator effects entail. Investigator effects refer to biases or changes in participant behavior or responses that occur due to the presence or actions of the researcher. When a researcher has a certain expectation or bias, their behavior—whether intentional or not—can influence how participants respond in a study. This influence can manifest through various subtle cues, such as body language, tone of voice, or even the wording of questions, leading participants to respond in a way that aligns with the researcher's implicit hypotheses.

In psychological research, maintaining objectivity is crucial for ensuring that the results reflect the true nature of the studied phenomena rather than the biases or expectations of the investigator. Thus, unwanted influence on the dependent variable is a primary consequence that can threaten the validity of the study's findings. Recognizing this potential effect is essential for researchers aiming to uphold the integrity of their data collection and subsequent analysis.