In the classification of experimenter effects, which aspect of a researcher…

Concept

An experimenter effect is a systematic change in participants' responses caused by characteristics or behaviour of the researcher rather than by the intended study variable.

These influences can be classified by the kind of researcher characteristic involved.

Application

An attitude is an evaluative psychological orientation involving beliefs, feelings, and behavioural predispositions. When a researcher's attitude is conveyed through expectations, tone, or interaction, it combines a psychological characteristic with the social researcher–participant relationship and may produce a psychosocial effect.

Contrast

• Age is primarily a demographic and biological characteristic; in this classification its influence is treated as a biosocial researcher effect.

• Race is a demographic and social identity characteristic; its influence is grouped with biosocial characteristics rather than the researcher's psychological orientation.

• Sex is a biological and demographic characteristic; its influence is likewise classified as biosocial.

• Attitude is psychological in content and operates through social interaction, which makes the effect psychosocial.

Cross-check

Separate psychosocial into its two parts: psycho refers to the researcher's psychological orientation, and social refers to its expression in interaction with the participant. Of the listed values, attitude directly supplies the psychological component.

Result

Therefore, the researcher's attitude is the aspect that may cause a psychosocial effect.