Knowledge hiding in academia—the reluctance to share one’s ideas, materials or knowledge with other researchers—is detrimental to scientific collaboration and harms scientific progress. In three studies, we tested whether (a) knowledge hiding can be predicted by researchers’ latent fear of being exploited (i.e., victim sensitivity), whether (b) this effect is mediated by researchers’ suspiciousness about their peers, and whether (c) activating researchers’ social identity alleviates or rather amplifies this effect. Study 1 (N = 93) shows that victim-sensitive researchers whose social identity as a “researcher” has been made salient are particularly prone to knowledge hiding. Study 2 (N = 97) helps explaining this effect: activating a social identity increases obstructive self-stereotyping among researchers. Study 3 (N = 272) replicates the effect of victim sensitivity on knowledge hiding via suspiciousness. Here, however, the effects of the same social identity activation were less straightforward. Together, these findings suggest that knowledge hiding in science can be explained by victim sensitivity and suspiciousness, and that making researchers’ social identity salient might even increase it in certain contexts.