This study investigated attraction and group cohesiveness under different visibility and anonymity conditions for social categories that differed in their capacity to be visually cued. Using computer-mediated communication in 36 mixed gender (visually cued category) and nationality (non-visually cued category) groups, we manipulated social category salience (via discussion topic), and anonymity versus visibility (via live video links). Under high salience, the effects of anonymity versus visibility were moderated by availability of visible category cues. Visibility increased attraction and cohesiveness for visually cued groups, whereas anonymity increased attraction and cohesiveness for non-visually cued groups. Path analysis showed that, under high salience, effects of visibility and anonymity were mediated by self-categorization processes, triggered by prototypicality of self in the case of non-visually cued groups under anonymity. In low salience conditions, visibility directly cued attraction independently from self-categorization, in line with relational attraction processes. Copyright © 2006 John Wiley & Sons, Ltd.