Age is just a number, but for some managers, one age group stands out as more difficult than others.

A survey of 1,344 managers and business leaders by ResumeBuilder said 74% of managers find Gen Z harder to work with than other generations, while 49% said they found Gen Z difficult to work with all or most of the time.

Respondents named lack of technological skills (39%), motivation (37%), and effort (37%) as the top reasons for managers being disappointed with Gen Z‘s work performance. Other reasons were poor communication skills (36%) and being easily offended (35%).

“In our organization, the Gen Zs I have interacted with can be exhausting because they lack discipline, and they like to challenge you,” Akpan Ukeme, head of HR at SGK Global Shipping Services, said in the report. “They think they’re better than you, smarter than you, more capable than you, and they will tell you to your face.”

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Furthermore, 65% of respondents said they had to fire Gen Z workers more than any other generation and 12% said they’ve had to fire a Gen Zer less than one week after starting.

“GenZ needs to work to understand what professional skills are needed to succeed in today’s workforce. However, the responsibility goes beyond GenZ,” said ResumeBuilder chief career advisor, Stacie Haller, in the report. “Educational institutions need to properly prepare students and managers and business leaders need to to learn to work with GenZ. Bias against younger workers is unacceptable and no different than the ageism that we typically see against Baby Boomers.”

The disconnect between Gen Z and the workplace could in part be due to the pandemic. According to a 2021 study, 46% of Gen Zers said the pandemic made pursuing their educational or career goals more difficult. Plus, when work and school moved to an online format, many Gen Zers never had the opportunity to fully experience an in-person office dynamic.

If Gen Z workers want to improve their workplace presence, Jennifer Stapleton, a leading manager at social media marketing and software company Social Rise, told ResumeBuilder that younger workers should focus on stronger communication skills, being open to feedback, and adaptability.

Related: Everything You Need to Know About Hiring and Retaining Gen Z Talent