Teacher’s nonverbal expressiveness boosts students’ attitudes and achievements: controlled experiments and meta-analysis

Abstract This multi-study investigation is focused on the debated issue of the educational benefits of lecturers’ nonverbal expressive behavior in online teaching. Six samples (N = 1465) were employed in three controlled experiments. Teachers’ nonverbal (NV) expressiveness led to more positive evaluations of both the teacher and the lecture. More importantly, it also contributed systematically to higher learning achievements, leading to a stable ad hoc ceiling effect. These strong effects have been systematically replicated in various samples and synthesized using meta-analysis. Achievements in the non-expressive condition showed wide variation, reflecting the differential motivational characteristics of the various samples. In two additional sub-studies, we examined the educational significance of teachers’ NV expressiveness (beyond effect magnitudes and meta-analyses) by investigating external motivators (incentives for excellent performance and framing the teacher’s high-prestige status). Both motivators boosted performance to the same ad hoc ceiling level. Educational implications for teaching in higher education, as well as the limitations of the research, were discussed.