Controlling the uncontrolled: Are there incidental experimenter effects on physiologic responding?

Area of Science:

• Experimental social science
• Psychophysiology
• Autonomic nervous system research

Background:

• Experimenter influence on participant behavior is a known concern in social science.
• In peripheral psychophysiology, direct physical contact between experimenters and participants is common, yet experimenter effects are not consistently tested.
• Understanding potential experimenter bias is crucial for the validity of physiological data.

Purpose of the Study:

• To develop and apply analytic tools for examining experimenter effects in peripheral psychophysiology.
• To investigate the influence of experimenters on participant autonomic nervous system (ANS) activity.
• To assess whether experimenter characteristics like status, gender, and race impact physiological measures.

Main Methods:

• Analysis of nine datasets comprising 1,341 participants and 160 experimenters.
• Utilized novel analytic tools to detect experimenter variance in physiological reactivity and baseline ANS activity.
• Examined experimenter effects related to status, gender, and race across multiple studies.

Main Results:

• Little to no significant variance in participants' physiological reactivity was attributable to experimenters.
• No substantial evidence was found that experimenter status, gender, or race influenced participant physiology.
• Despite controls, potential experimenter effects in physiological data remain a concern.

Conclusions:

• Experimenter characteristics appear to have a limited impact on participant physiological responses in the studied psychophysiology contexts.
• The developed analytic tools can help researchers identify and address experimenter effects in physiological data.
• Recommendations are provided for minimizing experimenter influence to enhance the reliability and replicability of psychophysiological research.