Investigate with your candidate what is keeping him from showing courage in certain situations.
Encourage your candidate to form an agreement with his superior regarding the way in which he could show more courage in his work.
Investigate with your candidate whether he has been in situations in which he showed courage while others did not. How come he managed to do so in that particular situation?
Investigate with your candidate whether he has been in situations in which he did not show courage while others did. What was the risk assessment of those others compared to your candidate’s? What stopped him from taking that risk?
Encourage your candidate to ask a colleague to signal him when the colleague feels the candidate is missing opportunities due to a lack of courage.