Two Brain Problem

One of those design problems that's solved by having two brains think about it at a time. Something interesting happens in the interactions between the brains: they become more than the sum of their parts. See SurgicalTeam, PairProgramming.

The interactions may help provoke thought processes in the same way that talking to a CardboardProgrammer, CardboardAnalyst helps - it's not the talking to someone that helps, it's the "talking". Verbalizing the thoughts means different bits of brain are involved in processing them - you need to serialize the thoughts and spell them out and generally organize them differently. See also RubberDucking.

Also, you've got two experience pools and two world views to draw from.

{My partner is also a software engineer, I have pitched the idea that my employer should pay him as well since we talk about our work to each other and hence effectively both our employers are getting the benefit from both brains thinking about their problems... this was not well received...}

-- KatieLucas