I have a client who seems to be pretty serious about separating work and outside life. He doesn't like it when people joke around in the office and tells people that business is serious. The business unit is quite productive but is it necessary to be so serious?

Humor in the workplace, especially when it deals with work-related topics, is a good thing. It allows individuals to surface issues and concerns in an indirect way and lets the culture as a whole address and relax some underlying tensions.

For some, "work" is treated in the Puritan tradition, meaning all work and no fun. However, preventing even light-hearted treatment of inevitable tensions can keep people apart and create an environment where those issues fester and grow. As long as the humor is not directed at any one person or promoted at any group's expense in a mean spirited way, humor is being recognized as a good thing. Recent articles in Harvard Business Review and other publications describe how humor is a a good indicator for the health of a company, something that traditional business evaluators do not address.

A good manager will actively manage and encourage employees to participate in and contribute to humor. Understanding the culture of humor in an organization gives a manager - as well as a consultant - insight into internal networks, influence, and communication. This is not an encouragement for consultants to "go native" and adopt the client's culture. It is an encouragement to better understand the culture through humor as well as through its business processes. 

Source: institute of Management Consultants – USA