[pcrh]

Not the same subject area, but this is why places such as Janellia Farms [1] restrict the size of their research groups. A PI with more than 6 people under her is considered a manager rather than a researcher.

[1] http://www.hhmi.org/janelia/

[thelittlelisper]

Well, Janellia is actually in my research area, so you pretty much nailed it.