This study explores the interpersonal faculty development interactions of university faculty as a function of their demographic representation (with regard to gender and ethnicity) in their home departments. For one academic semester, a small sample of 30 tenure-track junior faculty participated in a weekly diary checklist study in which they logged all their mentoring and professional development communications, noting the status of those involved in the interaction and the content. Demographically privileged faculty (whose gender and ethnicity were not underrepresented in their departments) reported more interactions overall, more with higher status colleagues, and more on content critical to retention. Extrapolating from the disparities revealed in this single semester (which benefitted demographically privileged faculty with an average of 13 more faculty development interactions), a gap amounting to 130 faculty development interactions could accumulate favoring privileged over underrepresented faculty by the end of a typical 10-semester tenure probationary period. Results warn of the need to attend to subtle accumulating privilege in the interpersonal professional development opportunities available in the academy. (Contains 5 figures and 2 tables.)