Researchers had all participants watch a video lecture on Zoom and then take a quiz. The participants were split into three conditions. Group 1 had all screens off (no one in the class could see themselves or anyone else). Group 2 had only their own screen off (they could see the rest of the class). Group 3 had screens on (they could see themselves and others).
If seeing others is distracting or causes anxiety because of equity issues, then Groups 2 and 3 should be negatively affected. If seeing yourself causes Zoom fatigue because of monitoring, then Group 3 should be really affected. But if, instead, seeing others increases engagement, then Groups 2 and 3 should do a bit better and if seeing yourself increases accountability then Group 3 should do a lot better.
It should be noted that there might be multiple different effects at play here. What these researchers were asking was not about the why this happens. They were asking if there is a difference first.
The lecture itself was part of an introductory psychology course and was pre-recorded. The instructor was unfamiliar to the students and was not visible on screen. After about a half hour lecture, the students were told to immediately switch over to their LMS to take the 15-item multiple-choice quiz.
The researchers found that those students who could see themselves and their peers scored highest on the quiz and significantly higher than those who had video off.