Making a joke in an email asking for a PhD vacancy?
TL;DR: Women rates funny guys as more intelligent. Are professors the same?


No, not really.  In ordinary conversation, nobody is expected to say anything deep or knowledgeable.  Making a joke at least shows more cleverness than many of the alternatives (such as chatting about the weather).  On the other hand, in a context where you might be expected to say something with real academic content, just making a joke instead suggests that you don't have anything else to contribute.  I think it would be better to try to engage with the subject matter, even if you are clearly not an expert yet, than to look like you are deflecting the issue with a joke.

The worst case scenario is making a terrible joke and seeming overly proud of yourself for making it.  Don't write to someone doing gene editing and say "Your recent papers are really impressive and have been getting crisper and crisper (get it? LOL!). I guess mi Cas es su Cas, am I right?"