Think twice the next time you decide to copy your boss in an email. That simple little “CC” box (抄送框) could send a message that ruins your relationship with the other receivers.

    A study in Harvard Business Review asked working adults to imagine that their coworker always, sometimes, or rarely CC'ed their boss in emails. The study results show that employees felt less trusted when their coworker “always'' copied the boss than when they ''sometimes” or “almost never” did. The results of the survey aren't surprising, says career expert Bruce Tulgan. Sometimes the boss really does need to stay in the loop (在圈内) with an email chain. But most times, employees are purposely sending the message that they don't think the receiver follow through with what they're asking unless the boss gets involved, says Tulgan. “That is an expression of lack of trust,'' he says.

    Breaking down that trust level in your office can have serious consequences. Like in any relationship, coworkers need trust to keep things running smoothly. “When people have trust, there is a much higher level of wanting to deliver for each other,” says Tulgan. “When people have enthusiasm, they try harder.” That means more willingness to take risks and make decisions, he says. Even if you don't trust your coworker to follow through for you, copying the boss in an email is not the best strategy, says career expert Todd Dewett, PhD. “CC'ing is the adult version of being a tattletale (告密者),” he says. “It tells your colleague you didn't agree without telling it to their face, and you want your boss to know without talking about it.”

   As a rule of thumb,only about 20 percent of what you do in the office is truly urgent, and those are the only times you should consider getting your boss involved in, says Tulgan. “The most important people, the most important project, key relationship,” she says. “That's when you might consider the occasional use of CC.”