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Background. Adopting expansive versus constrictive postures related to high versus low levels of social power has been suggested to induce changes in testosterone and cortisol levels, and thereby to mimic hormonal correlates of dominance behavior. However, these findings have been challenged by several non-replications recently. Although there is thus more evidence against than for such posture effects on hormones, the question remains as to whether repeatedly holding postures over time and/or assessing hormonal responses at different time points would yield different outcomes. The current study assesses these methodological characteristics as possible reasons for previous null-findings. By testing effects of repeated but short posture manipulations in a social context while using a cover-story, it further fulfills the conditions previously raised as potentially necessary for the effects to occur.
Methods. 82 male participants repeatedly adopted an expansive or constrictive posture for 2 minutes in between blocks of a task that consisted in categorizing faces based on first impressions. Saliva samples were taken at two different time points in a time window in which hormonal responses to stress, competition and other manipulations are known to be strongest.
Results. Neither testosterone and cortisol levels linked to dominance behaviors, nor progesterone levels related to affiliative tendencies, changed from before to after adopting expansive or constrictive postures. The present results establish that even repeated power posing in a context where social stimuli are task-relevant does not elicit changes in hormone levels.
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Results of mixed effects ANOVAs with the full sample.
Posture, Time and Posture*Time effects in ANOVAs conducted on the full sample before exclusion of outliers more than three absolute deviations above the median. η2p: partial eta-squared, η2G: generalized eta-squared.