As a grad student (or postdoc), past taking classes, is it ok to get a thank you gift for a professor who :
- has helped you with something (e.g. introduced you to someone for a collaboration or wrote you a recommendation letter for an application, or offered life-saving help with revisions for a paper without becoming a co-author)
- is not directly involved in any official evaluation (i.e. is not your advisor, is not on your committee, and you do not and will not have any classes with them)
- is in the same institution (and your "neighboring" department, e.g. say Physics and Math).
- might, in principle, still collaborate with you on a project in the future (but nothing is planned or discussed and there is no reason to believe such a collaboration is particularly likely to happen)
- might still recommend you for other opportunities (e.g. internships, collaborations, or fellowships) in the future
- you might still be a TA for in the future
Which of the above (if any) would be a reason for such a thank you gift NOT to be ok.
I am not asking what is in agreement with the rules and policies of specific institutions, but rather:
- What is the right, ethical, and fair thing to do in general, in such settings?
- What is the etiquette (in the US, or wherever you know the etiquette for)?