Millennials are hyper-focused on their reputations at work, according to research from Weber Shandwick and the Institute for Public Relations, which found that 47 percent of Millennials think about it all or most of the time compared to 37 percent of Gen Xers and 26 percent of Baby Boomers.

And while job performance and punctuality top the list of reputation builders at work for all the generations surveyed, networking and socializing during off hours are more important to Millennials than any other generation. A third (34 percent) of Millennials see meeting with colleagues outside the office as a positive driver of their work reputation, compared to 14 percent of Gen Xers and 15 percent of Boomers.

"Hanging out with colleagues after work might have been a nice way to kick back for a Gen Xer, but for Millennials it's a critical component of building their 'rep' or 'brand' at work and they take it seriously," says Leslie Gaines-Ross, chief reputation strategist at Weber Shandwick. "Our research shows that more than any other generation, Millennials believe that in addition to doing a good job, it's important to connect with colleagues to build their careers and create lasting impressions."

Millennials also place a higher value on building and maintaining a positive digital presence as a reputation booster at work compared to the other generations. Seven in 10 US adult workers who report to be social media users say that their work reputation is more important than their social media reputation. However, one in five Millennials (21 percent)—more than any other generation—believe both their work and social media reputations are equally important.

Says Gaines-Ross: "In today's digital world, it's nearly impossible to keep your work and personal lives completely separate. Millennials give greater weight than other generations to their digital and in-person reputations, which shows the influence of having grown up digital."

When it comes to behavior that can harm one's reputation at work, Millennials are less aware than their older cohorts how hearsay and feeding the grapevine can damage their reputations. Millennials are less likely to see the danger in saying negative things about coworkers than GenXers and Boomers (64 percent vs. 74 percent vs. 79 percent respectively) and engaging in gossip about colleagues (64 percent vs. 72 percent vs. 74 percent). Millennials are also more likely to believe that not socializing with colleagues outside of work can hurt their reputations (20 percent compared to 7 percent for Boomers).