Touch technologies have become ubiquitous, motivating researchers to explore their potential--especially in collaborative scenarios. Studies on collaboration using joint visual spaces like multi-touch tables have demonstrated positive effects on performance. Yet, factors like prior knowledge and preferences, resulting in cognitive biases, were neglected although they are likely to put additional demands on collaboration. Whether touch technology can support its users in mastering the resulting challenges remains an open issue. To address this issue, we employed a hidden-profile paradigm (e.g., Schulz-Hardt and Mojzisch 2012) to investigate whether the affordances of specific support functions realized in a collaboration support kit on a multi-touch table help to overcome established pitfalls of collaboration (prior preferences and discussion biases). The collaboration support kit comprised a joint space and private spaces. It allowed participants to push information from the private into the joint space, to jointly sort information within the joint space, and it provided automatic functions like merging information. To replicate traditional hidden-profile studies, triads in a standard hidden-profile condition (n = 25) exchanged information in a discussion; triads in the condition with collaboration support kit (n = 29) were additionally provided with the aforementioned functions. Our results revealed that groups with collaboration support kit available showed greater discussion intensity, more balanced discussions, more indicators of mutual understanding, and better decision performance than standard hidden-profile groups. This is original evidence that affordances of a multi-touch table with interactive support functions can be used to overcome biases from prior preferences and to enhance collaboration.