Sign of researcher's professional maturity When one applies for an academic position (especially for a permanent one) or for a significant funding, (s)he is often asked to show his/her professional maturity in research in the motivation letter/research proposal (or sometimes one is asked to indicate how (s)he would reach this maturity). 

The questions is: what are the signs of professional maturity in research that might be mentioned?

My background is theoretical mathematics but the question has little to do with a particular field as usually the positions and funding in question are for researchers from a broad range of scientific areas.
Signs of professional maturity in a researcher:


Having written and administered a grant proposal
Having been invited to sit on a review panel
Having been an invited speaker
Having guided or mentored students
Having organized a conference session
Having published a review paper