This trial seeks to establish whether agents selectively pay attention and retain information based on their type. The context is a college-level classroom lecture, party of a compulsory course, plus related mandatory reading material, with specific learning objectives examined through a written essay. The content of the lecture and reading material is on the environmental and health-related impact of the food industry. The hypothesis is that subjects who, before the lecture and exposure to reading material declared to be vegetarian or vegan, will retain more of the information they are presented with. This will be established through a text analysis of the written essays to be compared with a pre-registered list of concepts, which are related to the learning objectives. Effort and truthfulness in revealing the attained learning objectives are incentivised with study credit (grade for the essay) rather than monetary compensation. This trial aims to contribute to the literature on policy design to incentivise costly pro-social behaviour, and in particular on the merits and limits of information interventions.