A group of technical sub-surface teams undertaking a realistic industry project in an academic environment completed individual personality assessments. The resulting personality profile of a team has been used to identify performance issues, and has been related to team performance and peer review measures. For the teams studied, there appeared to be very similar average personality profiles and this was reflected in their similar performance. Individuals found the process of undertaking personality tests instructive. The teams had also undergone team role profiling so it was possible to compare role profiles and personality traits. Important aspects of collective team behaviour, such as openness to new ideas, conscientiousness, imagination, and attention to detail require a range of personalities playing their natural team roles, supported in their actions by the remaining team members. In teams, the conscientious nature of some people who pay attention to detail appears to count against them when it comes to peer review. A balanced team might be one therefore that has a better understanding of personality and team roles so that all beneficial traits are nurtured.