I’m highly sceptical about that.
I think all or at least most of the factors mentioned in this thread are part of it.
I would also add that it can be a reaction that occurs in a heated argument. In that context, even those of us who try our best to learn new information can get caught up with the desire to “win” that argument, or at least to not feel like you’ve completely lost.
I also think that the aforementioned desire to “never be wrong” may be a bit more localized. It may be a particular issue that they think they know a lot about. For example, the person mentioned in the OP may think themselves an expert on dogs.
As an undergraduate, one of our TAs in a history course had us break up into groups and without using anything for reference write down as many existing countries as possible. My group was going through Asia and when someone mentioned Mongolia I insisted that it wasn’t an independent country but was in fact part of China. I was in fact, wrong. But I insisted because I thought I was correct and we were in competition with the other groups and I wanted to win.
If only there were (notice the Conditional Tense there? Didn’t want to get N-picked) a web site for know-it-alls. One that would welcome, even encourage their picking of nits, and any topic would be fair game for them to drive off the rails and turn the discussion into a fight over one minor point.
That’d keep them away from proper society and let them pick at each other, unnoticed by normal folk who don’t care about their petty squabbles.
Hmmm, maybe a board they could leave messages on…
I agree positive reinforcement is a big part of it. Say you’re an insecure person, and one day you correct someone “actually you shouldn’t feed dogs peas”. The majority of people tend to just say “wow interesting thanks.” People are rarely paying much attention to one another, and even if they are, they’re not really interested in challenging someone who is (ostensibly) doing them a favor.
The result is that the person gets rewarded with a little boost of confidence, and that confidence makes them more likely to offer up random tidbits without thinking it through.
I find these folks really irritating, because I do try to fact-check tidbits like that, and their ego absolutely can’t handle it. Pull up Snopes or something and the reaction is either “sure buddy, go murder your dog, I tried to warn you”, or “what kind of pedantic jerk pulls out their phone to fact-check somebody who’s jUsT tRyInG tO bE heLpFuL”.
Tiresome people, and arguably harmful too (see: Ivermectin).
Nitpick (Someone had to, why not me): I would not describe “Don’t feed peas to dogs” as a nitpick; it is simply poor advice. “Don’t feed chocolate to dogs” is good advice and not a nitpick either. The other examples are true nitpicks. Since about half the world (my half) says basil with the same vowel as has and the other half says it with the vowel of bay, it is idiotic to argue about it. Likewise spelling such as check and skeptical. Incidentally, when I write one in US dollars, it is a check; when in Canadian dollars, it is a cheque. Since I have accounts in both countries, it is a useful convention.
I think this is it, along with what @FairyChatMom said upthread.
I know someone with whom I’m quite close who began using this as a coping mechanism in her business. Her business requires deep knowledge about constantly-changing rules and regulations. When someone would ask her a question, even if she wasn’t certain of the answer, she would respond with authoritative-sounding information and stand by it – even if she later learned something had changed. She discovered if she said something with enough authority, people would generally just accept it as true.
This soon bled over into her personal life. She once confidently asserted to me that “Thou shalt have no God before me,” was not one of the Ten Commandments, expecting I would not argue the point. (Me being a stupid atheist and all.) Unfortunately for her, she said it while she had her laptop nearby. I insisted she look it up.
More recently, she patiently explained to me that deer are the most dangerous wild animals, killing more people than all other animals combined. As a result, she had become quite terrified of the deer that occasionally wander through her place and cautioned me to do the same.
I’m sure she read this on some clickbait insurance advertisement and it never occurred to her that what they meant was that deer kill people when they run out into roads and collide with cars – not that deer are attack animals. I gently clarified this to her, because I wanted to spare her future embarrassment in making this ludicrous assertion to others. But I’m sure if I hadn’t, she’d have gone to her grave advising anyone who would listen that encounters with deer should be avoided at all costs.
Or do what I do when people tell me stuff without any evidence, shrug and ignore it.
OK, but if they say it in the form of text in a public forum?
Other examples (these are all things people saw fit to ‘correct’ me about:
- Humans can’t digest gluten
- Nothing bad can happen from a single click on a link
- Wild garlic is poisonous as soon as it flowers
- One slice of bread contains 7% of your RDA of salt
- You can tell the true capacity of one of those fake USBs just by plugging it in and looking at the properties (oh lord, did a lot of people drop that turd of untruth on me)
- You can report scams to the police by forwarding the email (seriously, that’s like trying to email the fire brigade when you smell smoke)
That seems a very cogent argument.
I believe English uses the letter “Q” much too seldom and when, in the wrong way. (Yes, Germans too, I know…)
And now I must wonder why nobody has yet made any reference to Dunning and Kruger. They surely play a role here, together with all the other good arguments exposed. Illusory superiority as well.
I don’t feel obliged to correct all the people who are wrong on the internet.
If someone I am in a discussion with comes out with something like your examples that is relevant to that discussion, yes, then I will address it at least to the extent of asking for a cite or noting there is no evidence for it, or whatever is appropriate to the context.
My problem is that I am already too much of a nitpicker, and it makes me annoying. I am slowly training myself that no, I don’t need to correct every single factual error that I see.
There’s a subreddit for this of course, confidently incorrect. It’s hilarious.
The stunt that most baffles me here is responding early to a question concerning something the poster states explicitly they really don’t know anything about yet proceeds to give a lengthy answer anyway. If you don’t know the subject, we’ll believe you. No need to prove it.
Great Og, the nitpickers were attracted to this thread like flies to shit.
I don’t so much mind being nitpicked or corrected when the nitpick is correct
And just what do you have against Noah Webster? It’s not our fault that he put out a better dictionary that Samuel Johnson.
He deliberately spelled many words wrong for no good reason except to prove, through rebellious orthography, that America was no longer a British colony, and to hell with their spelling. To this day Americans continue to spell many words incorrectly. 
I’ve seen the documentary.
"Lesson number one: People Are Assholes.
Lesson number two: First Learn Lesson Number One.
-Mr. Miyagi
To be fair, the comment is absurd in the same way that the joke is There’s the same mismatch between the first and the last part. The same misunderstanding of context. It’s the same joke
I’d see the same poor reading of the audience in the first row of lecture theaters, where the smart kids would sit and sometimes think that the obvious implied next question should be asked, as you would if you were engaged in a personal conversation with the lecturer – signalling that you are paying attention – as if everyone else in the theater hadn’t already seen where lesson was headed.
Uh, no. The spudhead in question isn’t that layered. They didn’t demonstrate any understanding that it was supposed to be a joke. Their only motive was thinking they were demonstrating brilliance by pointing out the gaping flaw, adding nothing of consequential value, just like typical nitpickers.
And now, this is heading into the nitpicking rabbit hole I so try to avoid.