The Role of Group Size in Reactions to Ostracism in a Social Media Context Stephanie J. Tobin1, Sarah McDermott2, and Luke French2 1 Australian Catholic University; 2 The University of Queensland Introduction Study 1 Study 2 Conclusions Being ostracised can threaten one’s sense of belonging, self-esteem, control, and meaningful existence (Williams, 2009). This holds true in a social media context when an online post is ignored by others (Tobin et al., 2015; Wolf et al., 2015). Being ostracised by everyone in a group is worse than being ostracised by only some of the people in a group (Abayhan & Aydin, 2014; DeWall et al., 2010). DeWall et al. (2010) found that when people were ostracised by everyone in a group, they reported the lowest feelings of belonging and exhibited the highest levels of aggression. Belonging increased and aggression decreased dramatically with acceptance by one group member, and to a lesser extent with acceptance by additional group members. This is consistent with social impact theory which predicts that social force increases by a power function with the number of sources (Latané, 1981). A stronger test of social impact theory would hold constant the level of ostracism (e.g., participants are ostracised by all or none of the group members) and examine whether the number of group members affects responses. This type of design would also allow us to examine whether the effect of group size is stronger in the case of ostracism than acceptance. Negative events are generally more impactful than positive events (Baumeister et al., 2001), so people might be more sensitive to being ostracised by a larger group than they are to being accepted by a larger group. Hypotheses: We predicted that levels of belonging, self-esteem, control, and meaningful existence would be lower when people were ostracised by a large compared to small group, and somewhat higher when people were accepted by a large compared to small group. Because our research question involved a moderator of ostracism, we examined both reflexive and reflective responses in our studies. The temporal need-threat model of ostracism posits that immediate, reflexive reactions tend to be quite uniform and insensitive to moderators, whereas later reflective responses are more likely to show moderation (Williams, 2009). Sample 330 American mturk participants (46% male). Design 2 (ostracism) x 2 (group size) x 2 (order of DVs) x 2 (reporting instructions) between-subjects design. Procedure Participants took part in an online introduction task (Wolf et al., 2015). They chose an avatar, entered their name, and wrote a short introduction. Their introduction appeared on the screen with 2 or 6 other introductions for 1.5 minutes. They could like other people’s introductions. They received likes from all or none of the group members. They completed need satisfaction (Williams, 2009) and affect (Watson et al., 1988) scales in counterbalanced order and based on how they felt right now or during the online introduction task. Results There were significant (p < .05) main effects of ostracism on belonging, self-esteem, control, meaningful existence, and positive affect. There was significant moderation by group size: Sample 206 American mturk participants (49% male). Design 2 (ostracism) x 2 (group size) x 2 (order of DVs) between-subjects design. Procedure Same as Study 1, but with two assessments of needs/affect (Williams, 2009): one right after the online introduction task (reflexive) and one after a reflection period and a 2.5 minute distractor task (reflective). We also assessed the extent to which the number of likes received was expected and embarrassing. Results There were significant main effects of ostracism on all DVs except for reflective control. There was significant moderation by group size: As predicted, group size influenced reactions to ostracism in both studies. Participants reported lower belonging and meaningful existence when they were ostracised by a large relative to small group. However, group size did not influence reactions to acceptance. These findings support social impact theory and extend it by showing that the number of sources has a greater impact when source behaviour is negative relative to positive. Moderation by group size was evident on reflexive responses (belonging and meaningful existence) and on reflective responses (belonging). It is possible that the number of ostracizing sources is more immediate and readily processed than other characteristics of ostracizing sources that do not moderate reflexive responses, such as group membership (Gonsalkorale & Williams, 2007) and agreement with the target on a discussion topic (Williams et al., 2002). Study 2 findings suggest that the effects of group size on reactions to ostracism could be due to embarrassment. The public nature of the ostracism in this study and on social media in general likely plays an important role in producing embarrassment and need threat. References Abayhan, Y., & Aydin, O. (2014). Ostracism in the context of the social impact theory: The effect of numbers of source and target on four fundamental needs. Turkish Journal of Psychology, 29 (73), 108-124. Baumeister, R. F., Bratslavsky, E., Finkenauer, C., & Vohs, K. D. (2001). Bad is stronger than good. Review of General Psychology, 5, 323-370. DeWall, C. N., Twenge, J. M., Bushman, B., Im, C., & Williams, K. (2010). A little acceptance goes a long way: Applying social impact theory to the rejection–aggression link. Social Psychological and Personality Science, 1, 168-174. Gonsalkorale, K., & Williams, K. D. (2007). The KKK won't let me play: Ostracism even by a despised outgroup hurts. European Journal of Social Psychology, 37, 1176-1186. Latané, B. (1981). The psychology of social impact. American Psychologist, 36, 343-356. Tobin, S. J., Vanman, E. J., Verreynne, M., & Saeri, A. K. (2015). Threats to belonging on Facebook: Lurking and ostracism. Social Influence, 10, 31-42. Watson, D., Clark, L. A., & Tellegen, A. (1988). Development and validation of brief measures of positive and negative affect: The PANAS scales. Journal of Personality and Social Psychology, 54, 1063–1070. Williams, K. D. (2009). Ostracism: A temporal need-threat model. In M. P. Zanna (Ed.) Advances in Experimental Social Psychology. New York: Academic Press, pp. 275-314. Williams, K. D., Govan, C. L., Croker, V., Tynan, D., Cruickshank, M., & Lam, A. (2002). Investigations into differences between social- and cyberostracism. Group Dynamics: Theory, Research, and Practice, 6, 65–77. Wolf, W., Levordashka, A., Ruff, J. R., Kraaijeveld, S., Lueckmann, J. M., & Williams, K. D. (2015). Ostracism Online: A social media ostracism paradigm. Behavior Research Methods, 47, 361-373. SPSP 2016; Stephanie.Tobin@acu.edu.au The effects of group size and ostracism on belonging and meaningful existence were partially mediated by embarrassment.