The present paper describes the Reciprocal Kit Build approach as a designed activity for collaborative concept mapping. We aimed to investigate the effect of differences in individual knowledge (both prior knowledge and knowledge on task) on knowledge transfer, collaborative product, and learners’ affective responses during co-construction of a concept map with the Reciprocal Kit Build (RKB) approach. We categorized learners into two groups based on their prior knowledge equivalence and their degree of shared knowledge reflected in the individual maps. The RKB approach allowed learners to create an individual map, to reconstruct a concept map from their partner’s map components (nodes and links), and to discuss similarities (or differences) between the initial map with the reconstructed map. The results showed that, following our proposed activity, transfers of individual knowledge regarding the shared and unshared knowledge were considerably high. Although, learners’ differences on prior and shared knowledge did not significantly affect the knowledge transfers and the final collaborative products, different group composition influenced the experiences of learners.