In cyberspace no one can hear you scream.

The perpetrator and the victim are familiar roles in any bullying scenario but a lot less attention is paid to the bystander.

Yet, statistically, your teenage son or daughter is much more likely to have the “walk on” part of bystander, particularly when the bullying is carried out in cyberspace. They may think they are doing nothing when they glance at hurtful comments aimed at somebody else tumbling in on a news feed on a social media page, but they are involved.

There are grades of bystanders, says clinical psychologist Sarah O’Doherty, which range from being actively involved and encouraging the bullying – “you may not be the person who instigated it but as soon as it starts up you jump in and start adding at the same volume” – right down the scale to somebody who is just watching and doing nothing.

“You are never neutral if you are a witness to bullying,” she explains. “You have a choice to either do something or not do something – either way you are making a decision about it.”…