Using Cultural Psychology as a framework, this research project aims to measure and analyze the heterogeneity of university teachers’ conceptions of intelligence. To this end, we have developed a new method of analysis: Heterogeneity by Contradiction Analysis (HCA). We conducted semi-structured interviews with 20 university teachers, presenting them with a series of short cases or vignettes depicting different facets of intelligence. Based on the discourse elicited, we first created a category system. Then, we pre-defined a series of possible contradictions among pairs of categories. Using these pre-defined contradictions, a systematic sampling of theoretical contradictions could be obtained from the discourse. Finally, a researcher reviewed these sampled contradictions in order to find and code real contradictions, which were later analyzed. 85% of all participants presented at least some heterogeneity in their discourse by expressing an idea and its opposite in different parts of the interview. The content of the discourse and its context are analyzed in the expression of heterogeneity, which yields future implications for research, intervention, and teacher training.