They studied this problem during World War II. The results were as clear and as unambiguous as the nose on your face.
Lemme tell you about these weirdos back in the early 90's. I was one of them. These weirdos consistently claimed in the workplace that you could get a hell of a lot more work done by running a monochrome monitor in the background when debugging. I used to ask for them all the time at all the places I contracted at. People looked at me like I had just stepped out of an alien spacecraft and asked where the earth women were at. Some people teased me after that for the length of the contract. "We will be getting those double monitors in soon, Cleve. One for each of your eyes. Will that make you code better?" They'd all laugh. Then they'd go back to doing nothing and waiting for me to finish up their project.
One really disturbing thing is that the majority of people in the workplace had no idea about the actual hardware architecture of the PC that sat on their desk. Most of them didn't know that a secondary monitor monochrome memory area was built into the stack in MS-DOS for the very reason that all serious computer programmers used a second monitor, especially when debugging any kind of graphical application for any reason. At places like Microsoft, which was a very productive company in it's early days, they were simply mandatory.
About two decades later, every company in the world has twin monitors on their employee's desks for the very reasons I understood in 1991. Mind you, it took two decades for them to adopt something I had deduced within two weeks of sitting down in front of a PC for the first time in my life … and even then they were basically copying other people for reasons they could not explain. I first realised the importance of dual monitor setups when coding for the Commodore 64 on top of a C-128 and discovering the second jack that was available for a completely separate monochrome display.
You can tell they don't really know why they have dual monitors on their desks. It doesn't really make a difference for somebody who does nothing anyway. It makes a colossal difference for a good programmer - upwards of 400% more productive in a given day when coding and debugging.
Nowadays, I don't ever mention anything about open plan cubicles at my contracts. There's no point. The company is purely theatrical anyhow, nobody cares if they ever produce anything. They are just going through the motions like automata. Deep down it is really about authority and dominance. The managers don't accomplish anything, either. They get the private office as a show of authority. They are better than you. They need to access high quality streaming porn all day in their offices and shouldn't have to worry about somebody looking over their shoulder. That's something you impose on software developers.
Here is the thing.
The research also shows that any gains in productivity by putting dual monitors on every desk are easily destroyed by requiring software developers to work in open office plans. This is what managers are supposed to do for a living. They don't know it. In addition to not knowing what they should know, they don't even know what they don't know. They don't know that they don't know what they should know despite knowing they know something when the evidence shows they are actually people who know less than nothing about anything.
When I have my own company (and I will) I will guarantee you my staff (working from private rooms) will outstrip every single place I have ever worked in terms of productivity. I guarantee you. I have been watching them all. Unlike them, I am a kind of 'boon who is a learning animal.