Leaders moderate the spectrum of personalities on the team.  Once the right people are involved, everyone’s opinion is valid and part of the process of arriving at the best decisions. Great leaders can moderate the spectrum of personalities to ensure it is safe for everyone. Doing this prevents the loud and confident ones from overshadowing the more reserved ones. These leaders appreciate that loud does not equal majority: just because no one counters the first arguments, it does not mean the silent people agree.  
 
First, the quiet ones are thinkers.  They have valuable insight but are not comfortable letting it out.  They need help creating a safe environment where they can talk without interruption and mitigate perceived confrontation.  Moderators bring them to life with round tables, where everyone is expected to talk. Participants are called upon directly and interruptions are pushed away.  Ground rules should also be listed up front, such as: no interruptions, no name-calling, respectful countering and explicitly stating that ‘no idea is wrong’. The quiet often open up after the leader instills confidence in them by publicly mentioning something they do well. 
 
Conversely, the loud ones, sometimes referred to as the thorns, are not afraid to give opinion. Their confidence allows them to speak up without the full background of the topic. They seem to have less concern for the potential for embarrassment and even fill in gaps of knowledge with unproven data. The leader’s role is to protect them for embarrassing themselves when they are ranting, while letting their ideas come out without being overbearing to others.  A secret to managing them is to give them a non-public opportunity to chime in on decisions before they go out to the group at large.  Often, they will feel like they have already been heard when it is time to go public, reducing the chances of requiring damage control later.   
                                                   
Give the quiet ones a voice and the loud ones the right stage.