Experimental evidence of chocolate rewards as an extrinsic motivator for academic performance among peri-urban and rural public secondary school students in Oye Ekiti Nigeria

This experimental study explores the role of food as an extrinsic motivational tool in education, focusing on the association between chocolate rewards and academic performance in peri-urban and rural public secondary schools in Oye-Ekiti, Nigeria. A total of 120 students (aged 13–16 years) from three purposefully selected schools were randomly assigned within schools to either a control group (n = 60) or an experimental group (n = 60) receiving chocolate rewards. A pre-test/post-test control group design with a 2 × 2 × 2 factorial structure was adopted. After adjusting for pretest scores in an ANCOVA, the experimental group showed significantly higher post-test performance than the control group, F(1, 111) = 66.49, p < .001, η²_p = 0.375 (large effect). No significant main effect of gender or treatment × gender interaction was observed. A significant treatment × school location interaction emerged, F(1, 111) = 4.15, p = .044, η²_p = 0.036, with larger gains in peri-urban schools. Sensitivity analysis using linear mixed models to address clustering (students nested within three schools) confirmed negligible between-school variance after fixed location effects, yielding consistent results. Extrinsic motivation increased significantly pre-to-post in the experimental group (t(59) = − 8.49, p < .001, Cohen’s d = − 1.10; large effect, interpreted cautiously). These findings suggest short-term associations between chocolate rewards and improved academic performance and extrinsic motivation in this Nigerian sample. Clustering effects were minimal, but results remain exploratory and context-specific, indicating potential for complementary use of low-cost incentives alongside broader educational reforms.