One reason it’s so tempting to try to cleave John and Paul apart is that the distinctions between them were so stark. Observing the pair through the control-room glass at Abbey Road’s Studio Two, [Geoff] Emerick was fascinated by their odd-couple quality:
“Paul was meticulous and organized: he always carried a notebook around with him, in which he methodically wrote down lyrics and chord changes in his neat handwriting. In contrast, John seemed to live in chaos: he was constantly searching for scraps of paper that he’d hurriedly scribbled ideas on. Paul was a natural communicator; John couldn’t articulate his ideas well. Paul was the diplomat; John was the agitator. Paul was soft-spoken and almost unfailingly polite; John could be a right loudmouth and quite rude. Paul was willing to put in long hours to get a part right; John was impatient, always ready to move on to the next thing. Paul usually knew exactly what he wanted and would often take offense at criticism; John was much more thick-skinned and was open to hearing what others had to say. In fact, unless he felt especially strongly about something, he was usually amenable to change.”
Joshua Shenk and Geoff Emerick, as quoted in The Power of Two, The Atlantic
In Their Own Words 