 What do Miss Drayson and Kylen Braynek have in common?
Every man in the Diplomatic Corps who developed a twitch or a quirk was shipped to Saarkkad IV to work under Bertrand Malloy, Permanent Terran Ambassador to His Utter Munificence, the Occeq of Saarkkad. Number two suffered from some sort of emotional block that left him continually on the horns of one dilemma or another. He was psychologically incapable of making a decision if he were faced with two or more possible alternatives of any major importance. No two men were alike, and yet there sometimes seemed to be an eternal sameness about all men. And he had his memories of Diane, dead these ten years, but still beautiful and alive in his recollections. Somewhere out there, the ships of Earth were ranged against the ships of the alien Karna in the most important war that Mankind had yet fought. To have shown himself to one of them would have meant instant loss of prestige. To violate the rigid social setup of Saarkkad would mean the instant closing off of the supply of biochemical products that the Saarkkadic laboratories produced from native plants and animals—products that were vitally necessary to Earth's war, and which could be duplicated nowhere else in the known universe. It was Bertrand Malloy's job to keep the production output high and to keep the materiel flowing towards Earth and her allies and outposts. A staff of top-grade men could have handled them without half trying. It's inefficient to waste a man on a job that he can do without half trying where there are more important jobs that will tax his full output. Not the worst ones, of course; there were places in the galaxy that were less important than Saarkkad to the war effort. Partial or total losses of limbs can be compensated for in one way or another. Miss Drayson was a case in point. It had taken Malloy a long time to get it into Miss Drayson's head that it was perfectly all right—even desirable—for her to keep secrets from everyone except Malloy. She came in through the door, a rather handsome woman in her middle thirties, clutching a sheaf of papers in her right hand as though someone might at any instant snatch it from her before she could turn it over to Malloy. She wanted to know what his reaction was going to be; it didn't matter because no one would ever find out from her what he had done unless she was ordered to tell someone. "Yes, sir," said Miss Drayson in a hushed voice. Miss Drayson stood there calmly, her face a mask; her emotions were a secret.
 They are both paranoid about what other people think.
 They externalize a lot of their thought processes.  They are constantly processing extreme amounts of details.  They both dislike interacting with other people.  They are both paranoid about what other people think.