Whether it's working with them in the lab, or as part of a study group etc., have any of you had bad experiences with another PhD student?

I've personally met a few students who openly admit to only doing a PhD for the title, and just wanted to stay at university to continue their undergraduate lifestyle (i.e. sleeping all day and drinking all night). I doubt most of them will stay the course, especially when it comes to annual reviews.

I've also experienced a fellow PhD student give me and my peers the silent treatment for days, after saying something 'too intelligent' in a meeting and 'showing them up'.

I have definitely seen students like that. I am even surprised how many end up getting PhDs. Is it making you depressed that some utter slackers do the absolute bare to scrape past the viva with major revisions while you work hard to both be called Dr? I sat beside someone in my office who somehow managed to "collaborate" her way to a paper and a thesis. Where all she did was ask people for advice or what they thought and wrote it down. I might be exaggerating but I do harbour some resentment but I don't think I have had any bad experiences per se.

Why do you ask? Are you having a bade experience?

I had a ton of frustrations like this. My department was very social and superficially everyone put a lot of time into helping one another. However, things got weird very quickly. For example there was one girl (in her third year) who was very vocal about having impostor syndrome. Basically after every seminar or workshop she'd tell us all that she would have asked a question but was disempowered by the power dynamic and suffering from impostor syndrome. When I asked a seminar question after my first month or so, she actually wrote me a thousand word email accusing me of bullying and harassing her, and undermining all her endless disadvantages etc (without bothering to ask me about my own).

In a similar way to the experience rewt mentioned, this student "collaborated" her way through her viva by making a lot of noise about how selfish and uncommunicative scientists were, until other people started writing her thesis for her out of guilt. Then from the minute she passed, she changed all her social media to have the word Dr in it, and began tweeting about how hard her PhD was and how uniquely resilient she was for getting to the end. Of course, she put on her CV that she had been "mentoring" all these other poor, useless students... the same ones who were writing her chapters for her...

That was a really stressful experience because it made the entire student cohort quite cult-like for several years. She'd criticise other students for what they had for lunch ("not vegan? Oh it is vegan, but is it ORGANIC vegan? Fine, but is it *locally sourced* organic vegan? Okay, it is, but..."), what they looked / dressed like (she once called me fat and ugly, which was charming), where they lived, what relationships they were or weren't in etc. It was as if there was a very narrow view of what was "right" -- occupied only by her -- and everyone else was wrong. It blurred every boundary between the personal and professional and made the entire experience into a stress. In the end, she created a loyal clique of people who would never argue with her no matter how bizarre the issue, and everyone else who was endlessly criticised for simultaneously doing too much (and showing her up) and not doing enough (and oppressing her).

I can't get too specific, but I'm currently dealing with a PhD student that I have to interact with on a weekly basis. They aren't a particularly kind person generally (i.e. they directly insult people and then call it 'banter'), and would be someone I'd avoid if interaction wasn't necessary. Myself and other students have said that they feel the need to 'dumb down' what they say in front of this individual so 1) they doesn't copy any ideas and 2) so they don't insult everyone for being 'smarter'. Ironically, this person is also very antisocial, so doesn't admit to needing help, nor seeks it out. In their mind, they are further ahead than they really are, so they don't realise that they are stuck between a rock and a hard place.