Cumulative technological culture is an intriguing phenomenon whose cognitive bases remain a matter of debate. For the influential shared-intentionality theory, this phenomenon originates in theory-of-mind skills. Evidence challenges it, stressing the role of learners' technical-reasoning skills. This discrepancy might be explained by a more specific role of theory-of-mind skills, notably in situations where the teacher communicates with the learner without visual access to what the latter is doing. We tested this hypothesis using a microsociety paradigm where participants (n = 200) had to build the highest possible tower in 2 conditions: Monitoring (communication with visual access) and Blind (communication without visual access). We also assessed participants' theory-of-mind and technical-reasoning skills. Results indicated that learners' technical-reasoning skills predicted cumulative performance in both conditions, whereas teachers' theory-of-mind skills were involved only in the Blind condition. These findings confirm the distinct but complementary roles of theory-of-mind and technical-reasoning skills in cumulative technological culture. (PsycINFO Database Record (c) 2019 APA, all rights reserved).