Students involve themselves in learning activities multidimensionally, including behaviorally, cognitively, emotionally, and agentically. This multidimensional involvement predicts important outcomes, but it is also possible that each type of engagement might have its own specialized purpose or function. To investigate this possibility, we proposed and tested the specialized purpose hypothesis, which is that each type of engagement has its own specialized function targeted toward a specific purpose, such as to boost achievement, social support, motivation, or well-being. To test this hypothesis, we conducted four meta-analyses, utilizing multilevel random effects models. Each meta-analysis tested whether type of engagement differentially predicted students' achievement (meta-analysis #1), social support (meta-analysis #2), motivation (meta-analysis #3), or well-being (meta-analysis #4). The database included 652 effect sizes from 62 studies within 54 articles involving 32,403 P-16 student-participants (M[subscript age] = 16.8 years-old; 51.2% female). All 62 studies measured all four types of engagement so that we could compare the relative strength of association between each type of engagement and each correlate. Behavioral engagement was the strongest predictor of achievement. Agentic engagement was the strongest predictor of social support. Cognitive engagement did not show a specialized relation with any outcome. Emotional engagement was strongly associated with both motivation and well-being. These findings generally support the specialized purpose hypothesis, but they also raise important and challenging questions for future theory and research about how to better conceptualize and measure each type of engagement.