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1.0 1.2 1.4 1.6 1.8 * (a) EMG (magnitude change) t0 t1 t2 t3 Zygomaticus activity by time and smile type Genuine Posed (a) * * EMG activity (magnitude) 0.5 1.0 1.5 Genuine Smiles Posed Smiles Zygomaticus activity by condition and smile type Control (n=24) Excluded (n=24) (b) EMG Activity (mangitude) 0.5 1.0 1.5 Genuine Smiles Posed Smiles Oculi activity by condition and smile type Participants & Procedure 47 participants completed a writing task in which they were to recall experiencing: • feelings of rejection and exclusion (exclusion) • waking up yesterday morning (control) They then completed a computerised smile discrimination task, viewing 20 smile trials (10 genuine trials, 10 posed trials; see Figure 1). At the conclusion of each trial, participants rated whether the smile was genuine or posed. Stimuli Expressions from ten people were used as stimuli in this study. Each person person provided a neutral expression, a posed smile, and a genuine smile. Genuine smiles were elicited in situ as the people experienced a positive stimulus (for methodological details, see Miles & Johnston, 2006). Smiling to Smiles after Exclusion: Social Rejection Enhances Affiliative Signalling Michael C. Philipp 1 , Michael Bernstein 2 , Eric J. Vanman 1 , & Lucy Johnston 3 1 School of Psychology, University of Queensland, Brisbane, QLD, AUSTRALIA 2 Department of Psychology, Pennsylvania State University Abington, Abington, PA, USA 3 New Zealand Institute of Language Brain and Behvaiour, University of Canterbury, Christchurch, NEW ZEALAND Method Background Results Conclusions Facial muscle activity is specific to smile type Duchenne smiles are associated with intentions to cooperate and good feelings (e.g., Mehu et al., 2007). This prosocial cue may be the reason that rejected individuals are better able to discriminate smiling expressions. Bernstein et al. (2010) later showed that rejected participants had a greater preference to work with others displaying Duchenne compared to non- Duchenne smiles. Although research to date has shown that feelings of exclusion enhance smile discrimination, none has examined whether feelings of exclusion also affect smile reciprocation. 1.0 1.2 1.4 1.6 1.8 * † (b) EMG (magnitude change) t0 t1 t2 t3 Oculi activity by time and smile type Genuine Posed Rejection enhances reciprocal smiling toward genuine smiles Figure 3. Mean EMG activity (t1, t2, & t3) by condition in response to genuine and posed smiles. (a) Only Excluded participants showed more zygomaticus activity when viewing genuine smiles compared to posed smiles (**p = .01). (b) There was no effect of exclusion on orbicularis oculi activity. Note: Error bars represent 95% CI for the repeated measure comparison (i.e., smile type) Figure 2. Mean EMG activity for all participants by time interval in response to genuine and posed smiles. (a) Genuine smile evoked greater zygomaticus major activity compared to posed smiles at t3 (*p < .05). (b) Genuine smile evoked greater orbicularis oculi activity compared to posed smiles at t2 (†p < .10) and at t3 (*p < .05). Note: Error bars represent 95% CI for repeated measure comparisons. Figure 1. Trials were composed of a central fixation cross (range 4000-6000 ms), a neutral facial expression (1500 ms), a smile facial expression (1000 ms), and a return to the neutral facial expression (4500 ms). EMG activity was averaged into 5 segments. Segments t0, t1, t2, and t3 were divided by the b aseline to compute magnitude change scores. EMG activity was averaged into 5 segments (see Figure 1). Segments t0, t1, t2, and t3 were divided by the b aseline to compute magnitude change scores.This method of baseline correction adequately solves EMG comparison problems related to the wide variance between individual's EMG response magnitudes and variance in electrode placements (van Boxtel, 2010). All participants showed more orbicularis oculi activity to genuine smiles compared to posed smiles, suggesting that the Duchenne marker is readily mimicked. Excluded participants showed more zygomaticus major activity to genuine smiles compared to posed smiles.This may indicate that excluded people are signalling greater affiliation intents toward genuine smiles. t3 t2 t1 t0 t3 t2 t1 t0 References Bernstein, M. J., Sacco, D. F., Brown, C. M., Young, S. G., & Claypool, H. M. (2010). A preference for genuine smiles following social exclusion. Journal of Experimental Social Psychology, 46, 196-199. Mehu, M., Grammer, K., & Dunbar, R. I. M. (2007). Smiles when sharing. Evolution and Human Behavior, 28, 415-422. Miles, L, & Johnston, L. (2007). Detecting happiness: Perceiver sensitivity to enjoyment and non- enjoyment smiles. Journal of Nonverbal Behavior, 31, 259-275. Questions? Comments? Email us: [email protected]
