In mythology twins represent both dualism and entanglement. Saturated with archetypal meaning, the figure of the twins unsettles divisions between nature and culture and – in its various incarnations as the double, doppelganger, shadow, or fetch – it troubles the notion of a unique, bounded self. This article draws on the indivisible intimacy of twins to examine the anxieties of influence and competition that disrupt claims within the ontological turn about theoretical and methodological innovation. The curious phenomenon of ‘twinning’, we argue, captures a sense of the dangerous intimacy that is operative not only at the level of empirical research on twins but also at the level of intellectual work itself where novelty is often cast in terms of breaking away from imitation to forge an identity that is original and singular. To unpack the burden of competition and originality that underpins concerns about methodological intimacy, we trace a path from ancient mythologies to foundational research in twinship. In exploring the tension between hardwired dis/similarity and entanglement through the potent figure of the twins, this article considers how we might address methodological questions about self-identity and intimacy within the ontological turn.