Background: When developing a domain-specific academic self-concept, students are not restricted to social comparisons; they may also make temporal or dimensional comparisons. Aims: The main purpose of this study was to examine whether these different types of comparison trigger paradoxical effects of praise and criticism in the sense described by Meyer (1992). University students participated in Study 1 (N = 120) and Study 4 (N = 83). The Study 2 sample consisted of 180 seventh to ninth grade students, and Study 3 investigated paradoxical effects with a sample of 130 elementary school students. Methods: Participants were presented with vignettes describing the results of 2 students (social comparison condition) versus 1 student in 2 subjects (dimensional comparison) versus 1 student in 2 subsequent tests (temporal comparison). In all cases, the results were identical. Participants were then informed about a teacher's response to these results (praise vs. criticism vs. neutral response), and were asked to estimate the ability of the 2 stimulus persons. Results: Study 1 and Study 2 revealed that dimensional, as well as social, comparisons following praise and criticism elicit paradoxical effects of perceived ability, reflected in corresponding estimations of student effort and teacher expectancies. There were no paradoxical effects following temporal comparisons. Study 3 did not reveal any paradoxical effects, thereby supporting the assumption that the occurrence of such effects depends on the level of cognitive development. Study 4 showed that the paradoxical effects found in Study 1 and 2 occur even when the sanctioned and the neutral achievement are presented independently. Conclusions: Dimensional comparisons, which have been largely overlooked in the past, play a major role in ability inferences.