Gender of the expresser moderates the effect of emotional faces on the startle reflex

Abstract

It has been suggested that the impact of emotional expressions on the startle reflex is influenced by the intention communicated by the expression (e.g., the intention to attack). However, we propose that the meaning of an emotional expression is not only based on the intention, but is also influenced by characteristics of the expresser such as gender: since men are typically seen as more dominant than women, anger expressed by men should be perceived as particularly threatening, thus amplifying the startle response. We compared the influence of anger, fear and neutral expressions shown by men and women on the startle reaction. Startle reactions were measured using electromyography. As predicted, we found stronger startle reactions after the presentation of anger expressed by men compared to fearful and neutral expressions shown by men. For female expressers, the startle response was not affected by expression type.

Keywords:

• Emotional expression
• Startle reaction
• Intention

Notes

¹ Please note that a recent study (Duval, Lovelace, Aarant, & Filion, 2013) failed to replicate the effect reported by Hess and colleagues (2007). However, the authors themselves note that because of the small number of stimuli used in their study, the faces might not generalise to the broader expression by gender categories (cf. Duval et al., 2013). Furthermore, calculations based on the results reported by Hess and colleagues, an α-value of .05, and power 1–β= .80 suggest that the study by Duval et al. might be underpowered with n = 23 (calculation was done using G. Power 3.1.3; Faul, Erdfelder, Lang, & Buchner, 2007).

² These startle probes were always administered during the ITI so that they would not disturb the task participants carried out between stimulus presentation and ITI.

³ We also checked for an influence of participants' gender on this effect. The only influence of gender that was significant was an interaction between expresser and participant gender: F(1, 38) = 11.54; p = .002, η_p² =.23. Simple comparisons showed that female participants showed a stronger startle response when viewing a male faces (M = .14, SD = .13) compared to a female face (M = −.13, SD = .14), t(20) = 4.65; p< .001. Male participants' responses did not differ for female and male faces (t < 1; ns). Importantly, the interaction between expresser gender and emotional expression was not qualified by the gender of the participant: F(1, 38) = 0.35; p = .704, η_p² =.02; therefore, this factor was dropped from further analyses.