Sounds like moving the goal posts to me. "Damage" is your word choice. It isn't too much to expect you to stick to your own definitions.
It is moving of goalposts, because we are not playing on the same field, with the same ball, or even playing football. So, I have to shift your frame of reference, or at least provide some vantage point from which you may understand a POV that's different than yours in that regard.
You said, and I quoted you word for word, that we need to establish "what it is damaging and why it is damaging". Now you say you don't need to do that? "No"?
The reason I put "damaging behavior" in quotes is precisely because it's a generic label for categories of behavior. I use term "damaging" to loosely carry over the disruptive structural alteration concept that may relate some meaning to you. But you can't understand what I'm talking about with a reductionist approach.
If you need a reductionist version... then we need to establish why it is damaging in a specific context we are discussing. Morality is behavioral model with contextual applications. The behavioral world is complex. We chunk it up into contextual categories of similar behaviors. We then see which behaviors are ideal, and we the distill these into "virtues". These behavioral ideals then serve as moral benchmarks.
If you didn't have the evidence, then you wouldn't be able to. That's kind of the point.
Well, no. First of all, the first point is to your OP - I don't need to prove something to you to be correct about something and point you attention by merely making a proclamation.
Secondly, it's not like there was no contemporary scientific research and literature. Just to cite you one example:
The tobacco problem : Lander, Meta, 1813-1901 : Free Download, Borrow, and Streaming : Internet Archive
It lays out very thorough evidence and appeal from both religious, scientific, and aesthetic POV as to why smoking is terrible, and does so in 1882! Of course, it's not the first of its kind either. Yet it took over a hundred years since the book publication for people to accepting these facts, with some still not thoroughly convinced even when evidence is widespread, or simply ignore these in broader context of hierarchy of values in which identity and pleasure are more integral to their sense of "well-being". And that's why we have these conversations.
So, the issue isn't evidence, but rather socially-mediated expectation of certain behavior. When smoking is glamorized and attached to masculinity and maturity, then appeal to evidence be irrelevant. If what means to be "a grown up man" would mean lighting up your first smoke, then health concerns are secondary in the hierarchy of values that one holds. We sacrifice health for "progress" or "status" all the time.
The point being is that there's much more to "convincing you" than you think is required, especially in context of psychological backfire effect when certain behavior is coupled to your identity.
We can't simply assume that when your beliefs are challenged then you acknowledge your wrongs and you alter your opinions. It happens in rare cases, but in most cases what actually happens is:
The Backfire Effect
On the other hand... you would have no problem of giving "provisional slack" to the items and claims that fit into your existing framework.
So, the true convincing usually takes a prolonged process of deconstructing emotional and identity attachment to certain concepts, and providing alternative frameworks of interpretation of reality, and that's not something that can be done in a moment where all one cares is to merely draw attention to unwanted behavior that you may ordinarily think is fine.
he same reason people refrain from scratching their butts in public. Perception. Just because people perceive swearing as low-class, low-intelligence, "subpar" behavior does not mean that they recognize it as actually being subpar. You need to explain why it is damaging and what it is damaging and what that damage is in an atheistic viewpoint. You can't simply appeal to:
Actually that's why they would abstain from swearing in public, because they
actually recognize it being subpar in that context. So, they are conforming to behavioral standards, and these standards have functional necessity. I don't have to give you a lecture on evolutionary biology, sociology and psychology to prove to you something
that you already practice in this very conversation

. You already know all of this, otherwise you are irrationally abstaining from using swear words as an underlining technique for communicating ideas.
I could point you to some psychology behind such taboo status on swearing. But you already know that swearing is a generic expression of wrath that is reactionary in nature. So, people don't swear, because it signals the same concept.
You already know that screaming out "N^&&%&r" as an expletive would be problematic in context of a mindset that uses that language in context of some angry outburst that floats up when reason doesn't suppress such presets of the mind. It doesn't matter whether one does it at home, or in public. So one should be concerned as to why they are doing that, and considering some therapy-driven approach to some of their sub-surface attitudes

.
There are plentiful sociological and psychological studies on this subject you can google up and verify and compare to. I don't understand why you would take a passive position to the subject and claim that someone has to put you through a class on theism and morality before that can communicate something that
you already generally practice.
So, there's nothing unreasonable about our expectation to elevate our communication to the standards of stoico-Christain virtues of patience and mercy when it comes to our behavior and word choice. That's all sorts of existing evidence that it's a good idea.
If you are going to insist that swearing has zero moral implications in private, then it's much like giving you a book about problems with smoking in 1982, which was my entire point about bringing that up as an analogy.
You haven't shown that "taking the Lord's name in vain" is anything other than this. All you've done is commit an ad populum fallacy. You've also changed the context from "at home alone" to "public speaking". You're trying to add extenuating circumstances to cloudy the issue. Stick to the question and "establish" what you said needs to be established.
Nick, I've already explained to you the ACTUAL context for taking God's name in vain. It's a scholarly context and not the one that's rooted in some modern-day colloquialisms. You choose to ignore it and shift it to people who don't understand the actual context and demand that you stop swearing in private? Talk to these people. I have no idea what their individual reasons for equivocating second commandment with, let's say using "Oh my God" as expression of concern for someone.
I will argue that "G/d" is problematic as an expression of wrath for the same reason why "F^&^n Jews" would be problematic expression of anger that's rooted in some subconscious attitudes that should be examined.
Uh-huh. Just like how shouting "Darn it!" when I stub my toe isn't a sin. Or even just "Ouch!". What's the difference?
This is where you misunderstand what this is about.
If someone stubbed their toe and yelled out "F-ing N^&$r" or "F^&^n Jews" in private. No harm done, right? Would you need to prove to that person all of the philosophical basis for problems with racism? Could you really do that in a conversation? I doubt it. These are not rational perspectives, so why would you think rationality would work?
The same in your case, screaming "G-d" in your kitchen is irrational behavior. What rational approach do you expect me to take in order to convince you that such behavior is irrational, if it should be first be rather obvious to you that it's irrational.
If you think that it's perfectly reasonable and rational, then YOU need to defend that position, instead of injecting irrelevant fallacies and demanding me to "establish" context.
So, let's begin with that. Do you think that yelling out "G/d it" is a rational behavior?