Ambient Awareness of Who Knows What: Spontaneous Inferences of Domain Expertise

Being aware of others' expertise is essential for knowledge exchange. Browsing social media has been shown to foster such awareness, often referred to as "ambient awareness". However, the underlying psychological mechanism has not yet been established. In a series of three preregistered experiments (total N = 445), we tested the notions that individuals make inferences about others' domains of expertise when being exposed to domain-implying social media posts, and that they do so spontaneously - that is, unintentionally and efficiently. Regardless of whether individuals were carefully reading, browsing through, or memorizing domain-implying posts, and whether they had an explicit goal to form an impression or not, we found consistent evidence that they made inferences about others' expertise domains, as evidenced by responses in a (false) probe recognition paradigm and explicit domain identification (Experiments 1 - 3). We also showed that they did so unintentionally (Experiment 2) and efficiently (Experiment 3). Spontaneous domain inferences are a plausible psychological mechanism for how ambient awareness of who knows what is achieved through regular social media use. Our findings provide causal evidence for the proposed mechanism underlying the link between social media use and expertise localization and highlight the role of social media posts in this process.