One of the most important things I've read is the post Conversational Cultures: Combat vs Nurture.
A very short summary: what that post's author calls "combat culture", and what I will call "idea culture" is typified by people being willing to disagree with each other's ideas directly. A conflict-avoidant culture, or "nurture culture" is typified by people affirming each other, and interpreting direct criticism or disagreement as an attack.
I would recommend reading the post, but I'm not writing this post to convince you to read it, more to get out some thoughts on the effective communication.
My stance: not neutral
I've been practicing direct idea culture communication my whole career, and it seems obviously better than the conflict-avoidant style.
I want to work with people who care more about their work than they care about their ego, or being superficially aligned during a conversation.
We're here to figure out the truth – I don't really trust my ideas until someone I trust has tried to argue with them. Working solo is a disadvantage because I don't get that check. Working in a conflict-avoidant culture is the worst case, because even though I can tell my ideas to people, nobody will tell me if they disagree with me, and as a result I feel like nobody is listening to me.
I do disagree with the post's author when they say that countersignalling (the sort of friendly insulting that often happens between friends) has any place in an effective idea culture – productive arguments are about ideas and any hint of insulting, even as a joke, tends to get ego involved when it shouldn't be.
What is effective idea culture?
Ineffective idea culture just looks like two people arguing without really listening to each other. They might throw out some worthwhile ideas, but they're not seriously working to test their ideas out.
Mid-level idea culture might still look like an argument, but without the frustration. The parties involved are iterating on their ideas during the argument.
The better the speakers are at idea culture arguments, the more clearly they will talk about the assertions being made, and the quicker they update their position when their counterparty makes a valid argument.
At higher levels it doesn't even look like an argument, it's just 2+ people having a discussion and quickly figuring out the Most Correct direction forward, as far as their human reason and experience are capable of. This post is a good description of the communication effectiveness spectrum.
Does idea culture make you disagreeable?
It shouldn't. If you honestly care about finding the best way to do something, you should want other people who care to be willing to share their thoughts with you when they differ from yours.
The people I've worked with who cared the most about doing the best job possible, and were willing to argue with me when they thought I was wrong, have tended to be the ones I most wanted to be friends with.