Dr Jean Lynch of the anti-bullying centre in Trinity College says the most common cause of bullying is that the bully feels insecure and will target someone who is more competent than they are to prevent them progressing.
"You can also have people who just feel they are superior, they are so arrogant, and they think they can treat people any way they like," she says.
There can also be a chain of bullying where the bully is being bullied by their boss and then passes it down to someone under them. Research at the Trinity centre found that some 70 per cent of those bullied said they were bullied by managers.
Researcher and consultant on workplace bullying Jacinta Kitt says the main characteristic of a bully is an inability to see wrongdoing in themselves. She says it is a myth that people targeted by bullies are weak or vulnerable. She says that anybody can be bullied but that competent, confident people are often targeted because bullies feel "deeply and profoundly threatened by their competence".
Kitt says that while there is some confusion about what exactly constitutes bullying she believes one ingredient is necessary.
"That ingredient is that someone sets out to get someone, that they set somebody else up to fail, in other words, when there is nothing constructive in it at all."
She says that having collaborative rather than competitive working environments is crucial to preventing bullying and that this is being increasingly recognised in management. Fewer than 10 per cent of people are motivated in an internally competitive environment, she says.
When bullying does occur it needs to be dealt with at an early stage and informally.
"In the region of 80 per cent of people do not want retribution or revenge, they just want it to stop," Kitt says.
Dr Mark Harrold, a clinical psychologist with an interest in this area, says he is most concerned that some management courses "almost teach people how to bully without being detected". It can occur in many different ways such as indicating that a person is no longer wanted, putting them on very difficult rosters or by not giving clear guidelines or objectives and then criticising people for not achieving these objectives.
Kitt says a leading Scandinavian researcher has called bullying "psychological terror". She has given talks in different countries but heard stories that were "carbon copies of each other. People describe it as torture".