TABLE 1.

Summary of the seven main forms of negative mentoring experienced by undergraduates in our study^a

Categories and definitions	Manifestations
Absenteeism (n = 31)  Mentor is physically or intellectually unavailable to offer guidance, feedback, or support to mentee.	Absence due to conference travel, fieldwork, or other commitments Too busy to offer guidance, oversight, or feedback Lack of response to meeting requests or emails
Abuse of power (n = 29)  Mentor acts in ways that take advantage of position of power or are inappropriate given the differences in rank or position between mentor and mentee.	Public humiliation, belittling, and name-calling Overly harsh reprimands or ill temper Intimidation Implicit or explicit threats of repercussions Coercion Micromanagement Excessive judgment Credit taking and blaming
Interpersonal mismatch (n = 12)  Mentor and mentee have dissimilar personalities, work styles, or communication preferences.	Mismatched personalities Different work styles Different communication styles
Lack of career and technical support (n = 33)  Mentor fails to provide needed career guidance or technical advice or is not invested in mentee’s research.	Insufficient career guidance Insufficient technical instruction Insufficient safety training Lack of investment in the mentee’s research Lack of investment in the mentee’s career development
Lack of psychosocial support (n = 19)  Mentor fails to provide encouragement or acts in ways that undermine the sense of trust in and respect for the mentee.	Insufficient encouragement Lack of trust in the mentee and his or her abilities Lack of investment in the mentee as a person Lack of investment in the mentoring relationship Other interpersonally inappropriate behaviors (giving unsolicited advice, sharing intimate details, insulting or gossiping about others)
Misaligned expectations (n = 23)  Mentor has unspoken or unreasonable expectations of the ­mentee or expectations that are misaligned with those of the mentee.	Unreasonable mentor expectations of the mentee Misaligned expectations between mentor and mentee Misaligned expectations about student’s ability or knowledge level Misaligned expectations about structure of mentoring relationship
Unequal treatment (n = 12)  Mentor treats the mentee differently based on mentee personal characteristics or choices or mentor preferences.	Discrimination Favoritism

^aWe define each form and indicate how many undergraduates in our study reported experiencing each form (left column). We also list the main ways each form manifested in undergraduates’ lived experiences (right column).