At its most obvious, this behaviour involves shouting, insulting or intimidating victims.
But bullying can include more subtle actions, says Alison Antes, a workplace psychologist who studies researcher leadership and management practices at Washington University in St Louis, Missouri.
A bully, by contrast, is typically not interested in developing relationships that allow their subordinates to grow professionally, says Keashly.
They might also dish out bullying behaviour on a whim, whether or not the person they are targeting has failed to perform well, she adds.
The case is part of a spate of allegations that have rocked major scientific institutions in the past year.
At Germany’s prestigious Max Planck Society, two directors were accused of bullying; and the UK-based Leverhulme Trust revoked £1 million in funding from palaeontologist Nicholas Longrich at the University of Bath following an investigation into bullying allegations.
If employees do not achieve their goals, good supervisors will give specific and constructive feedback, she says.
Naomi Ellemers, a social psychologist at Utrecht University in the Netherlands who has studied how people are treated in academia, adds that supervisors on the right side of the line will give people the time, support and resources to achieve their goals, and treat them respectfully.
These more subtle forms of malicious conduct can often cause the most problems because they tend to be difficult to detect and are open to differing interpretations, says Antes. What one person considers firm management, another might consider bullying, says Antes.
It is not difficult to imagine, for example, a Ph D supervisor giving a student a raft of unfamiliar experiments to complete, with a deadline that leaves the student stressed and working all night. The answer depends on the broader behaviour and approach, explains Loraleigh Keashly, a communications scientist at Wayne State University in Detroit, Michigan.