&gt; You hire different types of people when you&#x27;re pairing full time<p>Yes, extroverts, specifically.  :)<p>Even if you&#x27;ve been close friends with someone for twenty-five years (as is the case with someone I pair with for some problems), there&#x27;s still a fair percentage of your thinking that will have to be focused on social stuff: putting expressions on, conversational behavior, avoiding asides that take a second to think but would require a minute to explain, etc.   These are things that tend to occupy the same mental space as where I am thinking about the context of the code I&#x27;m writing, and while pairing can bring back some of that contextual thinking in the form of the other person, the bandwidth is so much lower that pairing seems useful mostly for learning, or for sharing a problem that I&#x27;ve already struggled with (so that my deepest thinking about the problem happened while I didn&#x27;t also have to run sociability at the same time).