When assigning people in a company to do knowledge- or research-intensive work, I can see the benefits of working in pairs. When I'm working as part of a pair on a difficult problem, I don't feel like I'm alone, incompetent, or somehow not measuring up whenever I run into unavoidable (but formidable) obstacles. I don't feel so bad because my partner is going through the same thing. When we report on our progress, it's less psychologically taxing because the burden of responsibility is halved. It might be an ideal way to do things in a lot of cases, because it doesn't completely alleviate the workers of responsibility, but distributes the load on each person to make it more bearable.