SHORT PAPER Social exclusion lowers working memory capacity in gay-men but not in heterosexual-men Daniele Paolini 1 | Mauro Giacomantonio 2 | Ilja van Beest 3 | Roberto Baiocco 2 | Marco Salvati 2 1 Department of Education Science, University of Roma Tre, Rome, Italy 2 Department of Social and Developmental Psychology, Sapienza University of Rome, Rome, Italy 3 Department of Social Psychology, Tilburg University, Tilburg, The Netherlands Correspondence Daniele Paolini, Department of Education Science, University Roma Tre, Via del Castro Pretorio, 20, 00185 Rome, Italy. Email: daniele.paolini@uniroma3.it Summary Because sexual orientation is a crucial factor in social discrimination, this study assessed how the working memory capacity of gay-men and heterosexual-men is affected by a social exclusion event (N = 88). To manipulate the experience of social exclusion participants were included or excluded from a game of Cyberball. To assess working memory capacity, participants had to recall a series of letters while per- forming math problems in an automated version of the operation span task. The results of this small study, showed the sexual orientation of participants interacted with variations in belonging such that being ostracized (but not being included) lowered the working memory capacity of gay-men relative to heterosexual-men. Implications for research on belonging, social exclusion, and stereotype threat are discussed. KEYWORDS Cyberball, gay-men, sexual orientation, social exclusion, working memory 1 | INTRODUCTION People are social beings who are strongly motivated to belong to social groups in order to gain and preserve security, well-being, and high self-esteem (Baumeister & Leary, 1995). When their belonging- ness to groups is threatened, for instance by exposure to a brief social exclusion event, strong negative reactions follow (Williams & Jarvis, 2006). Many studies based on a computerized ball-toss game— Cyberball (Williams, Cheung, & Choi, 2000)—indicate that participants report strong negative effects after less than a few minutes of exclu- sion (see meta-analysis, Hartgerink, van Beest, Wicherts, & Williams, 2015). Specifically, excluded individuals reported several negative consequences (Williams, 2009; Williams & Nida, 2011; see also Paolini, 2019), such as negative mood and low levels of basic psy- chological needs satisfaction (i.e., belongingness, self-esteem, control, and meaningful existence; Zadro, Williams, & Richardson, 2004). While literature on prejudice suggests that being a target of dis- crimination could lead both an internal attribution for the negative treatment that induces in distress consequences (Ong, Fuller-Rowell, & Burrow, 2009; Williams, Neighbors, & Jackson, 2003; see also Aquino et al., 2015) and an external attribution that elicits a self-esteem protection (Crocker & Major, 1989; Crocker, Voelkl, Testa, & Major, 1991); research on reactions to social exclusion instead evi- dences that being a member of a racially stigmatized group exacer- bates the negative intrapersonal effect of exclusion (e.g., Goodwin, Williams, & Carter-Sowell, 2010). In the present study, we sought to extend previous findings by (a) examining whether negative conse- quences of social exclusion are also amplified by belongingness to a group that is stigmatized on the basis of sexual orientation, and (b) by assessing the consequences of social exclusion by considering changes in participants' working memory capacity. 1.1 | Social exclusion and social categorization Several efforts have been devoted to understand how social factors affect the consequences for social exclusion. When examining non- stigmatized groups (e.g., Caucasian or Republican), prior research has provided mixed evidence. On one hand, individuals are equally hurt when excluded by in-group or by out-group members (Smith & Received: 6 November 2019 Revised: 14 March 2020 Accepted: 16 March 2020 DOI: 10.1002/acp.3661 Appl Cognit Psychol. 2020;1–7. wileyonlinelibrary.com/journal/acp © 2020 John Wiley & Sons, Ltd. 1