How to inform an emotionally abusive advisor I don't want to work with him? I am an incoming PhD student.  Before I applied, I chose a particular school because it had a specific PI.  (Of course, this is not a good idea, but I did not know better at the time.)  The PI is very famous in my field and was extremely excited about having me in his lab, going above and beyond to get me to work in his lab (e.g. private tours, etc.).  I believe he was partially responsible for getting me into this school, but I can never be certain.

I had to take a year off for medical reasons, but for the last year and a half, we have been in monthly discussions about what I will work on and what I will do, and he has been giving me lots of work to do before I arrive.  Up until just recently, it was obvious to both of us that when I came to the school I would be in his lab.  He expects me to skip my lab rotations and join his lab immediately.

However, I recently learned from a conversation with one of his postdocs that he has being emotionally abusive to one of his graduate students (e.g. comments along the lines of "you know everybody hates you").  I also learned that he has been completely ignoring one of his postdocs (as a result of which the postdoc hasn't published in the last year and a half), and that he gave away the project of his other graduate student to someone not in the lab, and then lied about it.

So obviously I'm not joining this lab.  What is the best way to break off this relationship?  I am concerned about him retaliating, as he has a lot of power in the department.  I also cannot share my true reasons for leaving with him, because then he would retaliate against the postdoc who told me.

Is this something that should be done via email?  Skype?  I saw him recently when I visited the school (and learned this information) so I did not bring it up then.  There are many other labs in the department so I'm not concerned about that.  But I am concerned about what the consequences might be for leaving his lab.  Also, what kind of excuse should I use?  My present excuse is "I am questioning my interest in sub-sub-subfield X and want to do rotations before I start working with you."
My answer assumes that you are convinced that your presumptive advisor is emotionally abusive, and that you have made a firm decision not to work with him.

However, you haven't given a first- or even second-hand account of abuse or neglect; it's also possible that the postdoc is blowing a personality conflict out of proportion by spreading false accusations.  The only direct red flag I see is your presumptive advisor's expectation that you will join his lab directly without doing rotations.  You may want to have a confidential discussion with another senior faculty member about your concerns, before jumping off this particular cliff.



Pretend that your presumptive advisor is a reasonable adult human being.  Talk to them in person.  Be straightforward and honest.  


  "Thank you for your encouragement and your support, but I have decided not to join your lab."


That's it.  You do not owe them an excuse, an explanation, an apology, or a description of your alternate plans.  (I think you do owe them thanks.)

If you would be more comfortable giving an explanation, then do so respectfully, honestly, and carefully.  But if you have no intention of working with this advisor in the future, do not suggest the opposite, even indirectly.  In particular, you should not say "I want to do rotations before joining your lab" unless you actually intend to join their lab after doing rotations.  It would be better to say something like


  "I have decided to do full rotations before joining any particular lab.  I want to explore a few different subareas, and I think the breadth of experience will help my long-term academic career."


Be ready for the advisor to pressure you to do a rotation in their lab, or to argue that you're actually damaging your long-term career by not joining a lab directly.  Thank him again for his advice and encouragement, but stick to your guns.  Or he might surprise you by being completely supportive and giving you good advice about other labs to work in.

Under different circumstances, I might suggest being direct about your suspicions of emotional abuse and neglect, but as you say yourself, that could backfire on the advisor's other students and postdocs.  That's their fight to have, not yours.

If the advisor is as emotionally abusive as you suspect, he may try to pull you into an argument or blackmail you.  He may say things like "I got you admitted to this department; you owe me." or "I'll have you kicked out of the program." or "I'm big and famous and important, and I know everybody, and you've just signed your academic death warrant."  Do not engage.  Do not argue.  Do not back down.  You have neither signed a contract nor sworn an oath of fealty.  The most you owe him is your sincere thanks and your future success, on your own terms.  Assuming you work in a healthy department, his threats are idle.

That said, you should have someone in your corner, just in case his threats are not idle.  Before you dump your advisor, I strongly recommend having an honest and confidential discussion with the graduate director, ombudsman, department chair, or another trusted senior faculty member.  (The other students will know who to talk to.)  Be completely straightforward about your concerns, especially about possible repercussions from your decision.  Hopefully they will reassure you that your concerns are groundless, or at least that someone else is willing to fight for you to be treated fairly.

If not, you're better off in a different department anyway.