When one joins a new team, they should focus on building trust first through some wins. Often, folks put too much emphasis on being friendly and agreeing/accepting everything, which does the opposite. Social cohesion does not build lasting trust. You build trust through your deliverables and resounding impact. I thought of writing down the approach I have seen work. I have spent most of my career at Amazon and what I have learned can be best summarized through Andy Jassy's quote:

"They sometimes confuse it with being nice to one another or having social cohesion or not challenging each other in meetings. That's not what we mean. What we mean is being honest, authentic, straightforward, listening intently but challenging respectfully if you disagree, and then delivering what you said you would. If you want to earn trust, if you say you've got something, deliver it. If you own something and it's not going well, be self-critical and fix it."

You can watch a video here.

I was discussing it with one of my colleagues, and they mentioned that to challenge or to disagree, you need psychological safety first. Generally, safety comes from trust, so if trust is built through disagreements, it becomes a chicken-and-egg (what came first) problem. Similarly, new folks often complain about a lack of freedom to make decisions (without freedom, how will I prove myself?). There are some interesting conflicts there, and it can get confusing.

One of the most effective ways I have seen folks navigate this well is to start from the place of "I don't know a whole lot as a new person, so let people ask more questions and audit my plan/approach, as it is going to make things better." Of course, be confident with whatever you do, but accept that you lack institutional knowledge so some initial audit and support structure is needed. Humility helps avoid defensiveness, and defensiveness is the kryptonite to building trust.

Once you are open to learning and listening, the other side will also see that you are sincere about it and that it is not about who has the authority. Please do not do things blindly because your manager or someone at a higher level (or more tenure) said so. One of the surprising things that I learned is that trust is also built by listening and acting on the feedback. If you act and work on given feedback sincerely, others will be able to see it and start trusting you as time progresses. One good way to check is if you are receiving the same feedback repeatedly. Why did you not hear it the first time somebody gave it?

Even when things are going well, avoid the urge to prove something. People think it helps build confidence, but that urge is a sign of immaturity. I have seen this mistake multiple times (and have made it myself), where disagreements revolve around our ego rather than the right outcome. You will build more trust if you keep your ego in check and handle situations with more humility. This is where being vocally self-critical helps.

If you start with 'I can learn more, I need to listen, and I want to get to the right outcomes,' even if you disagree with someone, they will see where you are coming from, and you will be able to disagree. Such disagreements are not personal, and even after an intense disagreement, you can have lunch/coffee with the person you disagree with because you have trust.

Earning trust is not a one-time thing. You work on it daily and you have to earn it (it does not come with titles or levels).

Now, there are also instances where you have to stand up for something, and it accelerates trust-building. The approach for that can be summed up by John Lewis' quote: "Never, ever be afraid to make some noise and get in good trouble, necessary trouble."