Whenever a group of people gets together, no matter the size of the group, a dynamic can take over called “Group Think.” The result is that people stop thinking critically, examining the evidence, or evaluating consequences and accept whatever the majority of the people decide.
This can be deadly when a company is trying to make a critical decision for its future. In a desire to get along with everyone, someone will suppress their opinion and not mention flaws they notice. Personally, I have seen a group of people make horrible decisions because of one strong personality.
Group thinking also applies to a small group of people in the Church. A few people sitting around talking about a person or a project can sway the mindset of everyone involved. For example, you might think that someone in Church is a good person, but when the group starts talking about them, you suddenly change your viewpoint, not because you spoke to them, but because the rest of the group shared their opinions. On the other hand, you might have questions about a person, and everyone seems to love them, so you adopt their attitude.
This is why the Bible is dead set against gossip and backbiting conversations. Instead, we are taught to be encouraging and see the good in people. Because the next time you share your thoughts about someone with a few people, you influence how the entire group views that person. Others may not see the good or the bad that you do, but now that you mention it, everyone else does too.