This article originally appeared in Small Biz Daily.

The assumption is that an adult with a steady office job would have a certain level of maturity, but unfortunately, that’s not always the case. Most people learn from a young age that not everyone is going to agree with you, and yet, when office conflicts strike, it’s amazing how childish some adults can be. From my experience coaching companies, pettiness can spread pretty quickly in a workplace if left untamed.

Before I begin any coaching session with a company, I sit everyone down and set the ground rules for the day. My number one rule is always to leave the pettiness at the door. I make sure that it’s clear that we are all adults that are getting together to solve problems and make effective change. Once everyone makes the promise to act their age, our sessions are much more productive.

Here are some of those ground rules to bring to every meeting:

Validate others’ opinions. It’s understandable if you disagree with someone’s ideas, but that doesn’t give you free reign to shoot them down. Just like you would want your opinion to be heard, others deserve that same respect. Come to meetings with an open mind, and be ready to make compromises – there doesn’t need to be a “winner” in every battle.

Listen to the facts before you react. Reality can sometimes hit like a ton of bricks, but don’t be that guy who makes a fuss anytime something doesn’t go your way – that’s what toddlers do. When something less-than-pleasing is shared with you, such as when someone is dissatisfied or you hear the company isn’t making the projected revenue, accept what is happening and don’t argue with it. When you close your mind to what’s happening around you, nothing can move forward, and that’s just not healthy for any business.

Don’t hide your mistakes. If you made an error, own up to it. Hiding things and lying about them is reminiscent of a five year old who broke mom’s vase and blames the dog. In a situation when you didn’t do the right thing, the only finger you should be pointing is at yourself, and I guarantee your team will be much more understanding when you’re honest with them.

Don’t hide problems. Similar to sharing your mistakes, don’t be afraid to discuss the issues you may be experiencing with your work or with others in the office. But share your thoughts in a way and place that inspires conversation and collaboration, such as in one-on-one check-in meetings, rather than in the form of blame or finger-pointing. This is not a license to complain, but an invitation to share ways to improve. Once any problems are out in the open, the team can help you take the steps to correct them. Being honest about issues is also a great way to prevent those mistakes mentioned above. Then, you kill two birds with one stone – resolving the issue and protecting yourself from more issues later.

Speak up. Just as you shouldn’t hide problems or mistakes, make sure you share your ideas with the team. Who knows, you could have the solution that no one thought of before, but by shying away, you’re giving up that opportunity. Even if you’re a junior member of the team, your ideas are important. Give yourself and your colleagues the benefit of the doubt that your ideas are great and that they won’t make fun of you for them.

When you go into every day at the office with a mature mindset, others will do the same. Leading by example is the best way to demonstrate the behavior that you would like to see – a principle that harkens back to early childhood education. It’s crucial that team members act like team members and support each other in the effort to succeed. You’re all in it together, after all, so there’s no reason to be immature and compete with each other when instead, everyone can be a winner.