Arrogance

We challenge it in a formal environment.

If someone is trying to force the next best thing onto the team, we invite them to a meeting where they present and justify why what they want to implement is worth the development cost, risk and maintenance. There is then a week cool off where people can investigate etc, before there is a discussion about the actual pro's and cons's, and a decision is made. It stops arrogance quite well.

Code reviews are another one, everything must have test coverage, the review must have been done by a (jr) developer then concerns addressed, then signed off again by a sr developer.

By putting strict processes in place, you dont give people the opportunity to let arrogance get in the way. But it takes dedication from everyone to get it in place. It takes management willing to take a small productivity hit to implement and stick to producing higher quality code with less personality interventions.

Knowledge sharing helps keep everyone on the same page and down to earth. Also dont confuse arrogance with confidence, there is often a very fine boundary.

Finally, everyone I work with was also assessed based on fit within the team. Places like Google call it "Googleyness" but is really just a good personality requirement for the company.