> Is there an easy and objective way to tell the difference?

Better question, does it matter? As you said, bad hires are expensive. We aren't talking about language barriers here, we're talking about behavior that comes across as (your words) capital A asshole. If the person is going to behave that way on the job and it drags the team down, does it matter why they behave that way? I know I wouldn't want to be stuck working with them.

> However, you seem to be stating (correct me if I'm wrong) that there are really two categories of situations here - situation A, where someone is an Asshole with a capital A, and situation B where you have a neurodiverse or immigrant candidate that is misinterpreting the situation and should not be dismissed based on their behavior.

Well, to be honest I think a lot of "capital A assholes" actually are neurodiverse – if not in the more common sense of ASD/ADHD/etc, then in the sense of narcissistic personality disorder, antisocial personality disorder, etc. But, there are limits to the extent of neurodiversity anyone can handle: schizophrenia is a form of neurodiversity too, but a candidate who exhibits florid symptoms of psychosis in a job interview is obviously not a suitable candidate at this time (but they might make an excellent candidate in the future if their psychosis remits). If someone's behaviour is somewhat outside the norm, but they show some insight, willingness to take on feedback and attempt to change, etc, they can still make a positive contribution to a team. If they appear to have no insight, no ability or willingness to consider the feedback of others, no ability or willingness to change or compromise or meet others half-way – it probably isn't going to work out.

> However, based on my (admittedly anecdotal, but extensive) experience situation A is probably something like 95% of the time and situation B is probably something like 5% of the time.

Do you actually know the split is really 95% vs 5%? Is it possible that, some of that 95% really belongs to the 5% but you didn't realise it?

A couple of strategies which might help: (1) force yourself to stop and think about other possible explanations, and whether you have any reason to think any of those other explanations could apply in that particular case; (2) try to gently broach the subject with the candidate, and try to see if you can get any information on the interaction from their perspective. Possibly, their behaviour may seem less unreasonable when you understand it from their point of view. Also, you can judge how open they are to receive feedback and responding to it – there is a big difference between "yeah, I could have handed that situation better" and a rigid insistence that they did nothing wrong.

I'm sceptical of intentionally putting any kind of "hidden test" in a hiring process. When the process is totally transparent – directly ask relevant questions about technical skills/knowledge/experience, soft skills, etc – I think that is fairest on the candidate, and minimises the risk of unintentional indirect discrimination–and I think lawyers who specialise in employment discrimination law would probably agree with that. I don't think that means one has to completely ignore any incidental feedback outside of the transparent formal process, but there is a big difference between incidental feedback and intentionally engineering a "hidden test". Also, I don't think one should rule out an otherwise good candidate on the basis of such incidental feedback without some serious thought and investigation.

I don't completely disagree with your objection to the term, I think it is a term worthy of being critiqued. But, sometimes, when one is trying to communicate, the best option is to choose language which the majority of one's listeners will understand, even if one views that language as being in some ways flawed; choosing less flawed, yet less familiar, language may make it harder for the average listener to appreciate the point, and discussing the pros and cons of different terminological options can be a distracting detour which may also stand in the way of getting the primary point across. I think you are objecting, not to my point, but rather how I put it, because I think I could have made the same point without using that term. (And the same applies to my use of "culturally diverse", albeit for somewhat different reasons.)

To be fair, the comment you were replying to was strictly a response to someone's personal claim, not about the taxi driver scenario in particular

English is a tricky language, and in my reading of GP i was incredulous at the word "never", especially since service workers can be in bad moods or stressed and that becomes, to you (or me, or GP), external stressors.

Maybe i'm a bad person?

Some time ago I spent a lot of time in youth hostels. A pattern I noticed was that people from all different cultures were polite and considerate until the number of people in the immediate group whom they considered allies in some way crossed some threshold at which point they became jerks, disregarding rules and politeness and generally acting as though they were the only real people there. I was in Europe, so most of the large groups were also European, but I at least saw German, Spanish, and French groups behaving this way. I met many Australians, but they were always traveling singly or in pairs and always stayed polite as far as I could see. I also have a vivid memory of Americans on a train in southern Germany voicing their opinions loudly and rudely about homes they saw passing by outside the train windows. It was just three or four Americans, but the arrangement of people on the train gave them a local majority.

I suspect it is this dynamic more than tipping culture that gave rise to the stereotype of the ugly American. In small numbers people in foreign lands try to stay quiet and unseen. In larger numbers they feel safe and, maybe because they feel free from consequence or maybe as a stress reaction, they become worse than their normal selves. It isn't just Americans. But for a period in the last century Americans were the folks with sufficient money to show up in other people's countries in tour groups.

Also, the people who create the stereotype are the ones who are noticed. If there are lots of foreigners blending in and a group of them who don't, it's the ones who don't who create the reputation for the rest.

The Arrogant American became the Arrogant German (1990s / 2000s), and is now often the Irate Brexiter.

Being identifiable (appearance, langauge), significant in number, and crossing some threshold of observably obnoxious behaviour tends to leave impressions.

Within the US, you'll often find neighbouring-state stereotypes: "massholes", Texans (particularly in Colorado), Californians (Oregon), New Yorkers (city, everywhere), Yankees (the South), Southerners (the North), city slickers (country), country hicks (cities).

Much of this is inherent tribalism and not matching local patterns of speech, behavioiur, specific local knowledge, and the like.