Fascinating report by Alistair Cockburn: Characterizing people as non-linear, first-order components in software development. Some highlights:

I finally concluded that there is something there, in front of us all the time, which we are not seeing: people. People’s characteristics are a first-order success driver, not a second-order one. In fact, I have reversed the order, and now consider process factors to be second-order issues.

Most of my experiences can be accounted for from just a few characteristics of people. Applying these on recent projects, I have had much greater success at predicting results and making successful recommendations. I believe the time has come to, formally and officially, put a research emphasis on “what are the characteristics of people that affect software development, and what are their implications on methodology design?”
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Being good at communicating and looking around counter inconsistency, leading to the prediction that methodologies can make good use of low-precision artifacts whose gaps are covered by personal communication. Project histories also support this prediction, subject to the normalization of an adequately skilled staff, including management.