A new paper examines whether smartphone Bluetooth technology, working with small wearable beacons, can detect when young adults are physically near their peers in everyday life. The aim was to move beyond self-report, which can be inaccurate or biased, and test whether passive sensing could identify socially risky situations in real time.
The study involved 21 young adult participants and 55 peers over three weeks. Peers carried small Bluetooth beacons, while participants had an Android app that scanned for those beacons and prompted ecological momentary assessment reports. A beacon encounter counted as meaningful when the beacon was detected within roughly 15 feet for at least 15 minutes, after which the app sent a signal-contingent notification. This meant the beacon system was being used not simply as a tracker, but as a way of identifying sustained peer proximity that might matter for behaviour and intervention design.
Overall, the findings suggest that beacon-based peer detection is promising but still imperfect. The system showed good acceptability: 90% of participants completed the protocol, response rates to app prompts were around 76% to 79%, peers completed 93% of weekly surveys, and peers reported carrying their beacons on 96% of days. Participants generally found the app easy to use, and the researchers judged the protocol to be workable in day-to-day settings.
The paper concludes that Bluetooth beacons have real value for detecting peer proximity in real-world settings, especially for research on health-risk behaviour and just-in-time interventions. The beacons were feasible and acceptable enough to support proof of concept, but technical issues and reliance on peers carrying a separate device limited accuracy.