The Instant Message Generation Gap

The trend is driving a shift in workplace habits, as employees respond to a stream of instant messages while toggling among email, voice mail and other tools. While some older workers who have grown up with email see IM as annoying or distracting, they’re finding “you adapt or you die,” says Allison Tabor, a San Ramon, Calif., executive coach.

Andy Pittman, 54, resisted using instant messaging for as long as possible last year after becoming a senior executive at ShelfGenie, an Atlanta-based home-improvement franchising company. While most of his colleagues, who are in their 30s and 40s, communicate via Slack, Mr. Pittman, who became chief executive officer in January, preferred email.

Slack, one of the most widely used messaging apps, allows group chats, direct messaging to individuals, and voice and video calls across multiple devices. Mr. Pittman learned to use Slack after colleagues pressed him to do so. But he drew the line when they insisted he create a cartoon bitmoji to represent himself on the app. A colleague offered a gift card to any co-worker who could design one Mr. Pittman liked, but he wound up rejecting all 10 of their images, including one that portrayed him as a Teletubby. “I didn’t think any of them looked like me,” Mr. Pittman says. He posted a photograph of himself instead.

While email is still the leading form of business communication, IM accounts are expected to grow 8% annually for the next four years, to 8.6 billion world-wide, says the Radicati Group, a Palo Alto, Calif., research firm. Employers say they reduce the need for meetings and make it easier to sustain conversations among team members, share updates and get quick tips and answers. Email can seem clumsy, slow and officious by comparison.

While young workers tend to enjoy the social ties instant messaging can promote, some older workers see all the banter as TMI. Tim Tolan sets aside one channel on Slack for personal photos, videos and stories posted by his employees, who are mostly in their 20s and 30s. Mr. Tolan is CEO of the Tolan Group, a St. Augustine, Fla., affiliate of the Sanford Rose executive-search network.

Mr. Tolan, 59, admits he’s taken aback sometimes by what employees share, including photos of their lunches. “I come from a different era, and I tend to be a little more of a private person,” he says. “I don’t really need to see a plate of spaghetti.” But he recently bent to the trend by posting photos of his Costa Rica vacation with his wife. “I don’t want them to think I’m an old fogey,” he says.

Younger workers also tend to be more comfortable with taking instant messaging home with them. Nearly one in five employees who drive send or read work-related text messages while driving, according to a 2017 survey of 1,146 employees. Employed drivers under 45 are more than twice as likely to text behind the wheel as those 45 and over, says the survey, conducted by Harris Poll for Travelers Cos.

Some employees feel tethered to their screens by the apps’ status indicators showing whether they’re available or away. “For some, it makes them nervous that the boss can see their status as unavailable, and maybe judge them, when they’re actually making time for reading,” says Nancy Ancowitz, author of “Self-Promotion for Introverts” and a New York career coach.

The tempo of IMing changes the way many people organize their days. “It used to be that one of the big time-management tips people would recommend is to not read your email and just work uninterrupted for a few hours,” says Christina Seelye, CEO of Maximum Games, a Walnut Creek, Calif., videogame company. Now, taking a break from instant messaging for even a few hours can mean you’re missing something.

Many younger employees enjoy the slang and abundant emojis that mark IMs, saying they’re relieved not to have to worry about sentence structure or punctuation. But Kimberly St. Clair, who is 49 and the controller for Maximum Games, worries that when people get lazy about grammar, she does too. She tries to communicate professionally. “I shame my own self when I get sloppy,” she says.

Many employers use a hodgepodge of messaging and collaboration apps, making it hard to find information and people. And some allow teams and departments to choose different apps based on their preferences, says Art Schoeller, a principal analyst at Forrester Research. “The sprawl problem is still one that challenges everybody,”​he says.

Although Maximum Games uses five different messaging and project-management apps, toggling among them doesn’t bother 28-year-old Geoff Mendicino, a quality-assurance specialist for the company. “It’s a way for me to organize my thoughts,” he says. “I can switch between apps in the blink of an eye.” That means using Slack for messaging U.S. colleagues and Skype to chat with co-workers based in Europe.

A new generation of workplace apps, including Microsoft Teams, Stride by Atlassian and Google Hangouts, aim to simplify communication by bundling instant messaging with team-collaboration, web-conferencing and social-networking tools.

And more employers are teaching workers to avoid IM pitfalls. Udemy, a San Francisco-based marketplace for online classes, trains its new employees to curb distractions by customizing IM notifications to suit what they’re working on, says Shelley Osborne, head of learning and development.

Tony Hopp advises employees at his company to avoid falling into the trap of expecting all messaging to happen at warp speed. “Don’t assume that if you don’t get a message back in two minutes, your co-worker is ignoring you,” says Mr. Hopp, chief technology officer at AdvantaClean, a Huntersville, N.C., franchiser of environmental cleanup services. And when you send an instant message, include a note on when you need a response.

Write to Sue Shellenbarger at sue.shellenbarger@wsj.com