Answer:
Groupthink.
Step-by-step explanation:
This is a psychological phenomenon that occurs within a group of individuals who desire for harmony or conformity in the group. This desire is greater than anything else given that they would make or accept irrational choices to mantain that harmony. It's what has happened to Peter, he disagrees with many of the company's processes but decides not to speak against it as his team, the rest of his group, is in favor of the changes. To avoid creating a negative effect, he says nothing.