 What is true about the world these characters live in?
He was a captain of guards in Estates-General Correctional Institution—better known to its inmates as the Jug—and if he hadn't been able to detect the scent of trouble brewing a cell-block away, he would never have survived to reach his captaincy. And, what was more important, why she couldn't adjust herself to it, now that she was in. And O'Leary was a man who lived by the book. That old witch Mathias never told me I was supposed to mop up. From the born mechanic and the man with the gift of gab, society evolved to the point of smaller contact and less communication between the specializations, until now they could understand each other on only the most basic physical necessities—and not even always then. The ultimate should be the complete segregation of each specialization—social and genetic measures to make them breed true, because the unspecialized man is an uncivilized man, or at any rate he does not advance civilization. And letting the specializations mix would produce genetic undesirables: clerk-laborer or Professional-GI misfits, for example, being only half specialized, would be good at no specialization. And the basis of this specialization society was: "The aptitude groups are the true races of mankind." He was civil-service born and bred, and naturally he was proud and content to do a good, clean civil-service job.
 People are segregated by career, and not allowed to mingle with other groups or switch jobs.
 They all live under the impression they can only perform one job for their whole life.  People are segregated by career, and it's incredibly difficult for them to meet other groups and switch jobs.  People are segregated by career, and not allowed to mingle with other groups or switch jobs.  People have evolved to only be capable of one "specialization" through their lives.