Forget that game of computer solitaire. The biggest culprits in wasting office workers' time are … other office workers.

A variety of studies confirm this seemingly self-evident fact, Wall Street Journal columnist Sue Shellenbarger reports.

The problem has been exacerbated by workplaces with open floor plans and low-walled cubicles and fewer private offices.

The idea is that encouraging employee interactions will produce useful, profitable ideas like antigravity machines and death rays. Instead, it seems workers talk about sports and sex — useful fields of endeavor but not if your company produced, for example, truck axles.

Instead, the open plan, according to the Journal, has "an unintended downside: pesky, productivity-sapping interruptions." And there are data to prove it.

"Face-to-face interruptions account for one-third more intrusions than email or phone calls, which employees feel freer to defer or ignore," according to a study in the journal Organization Studies.

That suggests one quick way to boost productivity: bad manners.

Researchers at the University of California, Irvine, find that cubicle dwellers are interrupted 29 percent more often than those in private offices. A study by a Michigan State psychologist shows it takes just more than two seconds to lose a train of thought but 25 minutes to fully pick it up again.

Some employees, when they don't want to be interrupted, put on a special hat or armband or, at one office, drape themselves in crime-scene tape. Unmeasured is the amount of time the employee spends thinking, "Am I looking like a real idiot here?"

The Journal says more than 6,500 workers each year download a free "Interrupters Log Work Sheet" to help them analyze and eliminate sources of distraction.

What does not seem to be addressed in any of these studies is how much productive time is wasted filling out forms, logs, questionnaires, time sheets and computer Q-and-As on how much time is being wasted.