The security community has used psychological research on attacker personalities, but little work has been done to investigate the personalities of the defenders. We surveyed 43 security professionals using a Five Factor Model-based test to reveal common dominant traits. We found that our sampled population demonstrated that they were highly dutiful, achievement-striving, and cautious; in addition, they were high in morality and cooperation, but low in imagination. We conclude that many of these characteristics are appropriate for security professionals, although the low scores in the “openness to experience” domain may indicate difficulties in devising new security defense methods and in anticipating new forms of attack. This potentially leaves large organizations and nation-states vulnerable to attacks.