To intervene in a co-worker's behavior is to audibly and visibly challenge it with the purpose of getting it to change.
We intervene all the time. When a child runs after a ball into a busy street, we snatch her up and say "no!" When a person in our household is lying around, sometimes we say "please take out the trash."
On the other extreme, if someone is in a violent rage, we sometimes ask the police and the justice system to intervene to stop the violence and and try to prevent is recurrence.
Human relationships in the workplace involve a lot of routine intervention.
- "You came late to work. Please arrive on time in the future!"
- "Stop! Get someone to help you when lifting more than 60kg."
- "Your software contains a defect, number 521. Please correct it."
This is totally normal stuff.
So is intervening to correct bad behavior in the workplace.
For example, if one coworker is gossiping and making jokes about another's appearance, that's bad behavior. If one coworker is blaming another for his mistakes on the job, that's bad behavior.
A good way to intervene is to make an "I" statement. That has a standard template as follows: "When you make jokes about A, I am uncomfortable. Please don't make that kind of joke any more."
- Describe the behavior
- Describe its affect on you personally. Speak for yourself. That's the "I" part of the statement.
- Ask for a change.
A not-so-good way to intervene in this example might be "When you make jokes about A, you make him uncomfortable." That's because you are no longer speaking for yourself. In this case, you invite a debate about whether he in fact is uncomfortable.
If you are a supervisor, your "I" statement can be a "we" statement. "When you don't finish your work on time, I have to explain why our team is behind schedule. Please try to finish your work on time. Is there any way I can help you do that?"
When you intervene in bad behavior by confronting someone, it takes them a while to absorb your input. Everybody has a time constant. If you walk up to somebody who trusts you and truthfully say "you are wrong," some people will take an hour to agree with you. Some will take a day. Some will take a year. It is helpful to figure out how long the time constant is for each person you work closely with. The key point is this: it will never be immediate.