Why does Gene not have an interest in Brinker in the book A Separate Peace?
Gene does not have an interest in Brinker because over the summer, his values have solidified. Gene has learned to appreciate the innocence and sincerity of life and relationships during the carefree summer months. Brinker Hadley, as the big man on campus, represents the calculating and manipulative efficiency of the real world, and Gene, having discovered something more valuable than that, is not interested in courting his favor.
When the winter session begins and standout students like Brinker return to Devon, Gene observes,
"We had been an idiosyncratic, leaderless band in the summer, undirected except by the eccentric notions of Phineas. Now the official class leaders and politicians could be seen taking charge, assuming as a matter of course their control of these walks and fields which had belonged only to us...Brinker Hadley had established his headquarters (and) emissaries were already dropping in to confer with him."
Gene compares Brinker's position as "the center of all the excitement and influences in the class," and his "steady wit and ceaseless plans," to his friend Leper Lepellier, whose collection of snails has been "replaced by Brinker's files" in the room which had over the summer been Leper's. Leper represents innocence, and a connection with nature, while Brinker represents the machinery of men and society, and, in this particular setting, the war. Having experienced for a little while the halcyon, uncomplicated days of summer and the innocence it entailed, Gene is not yet ready to let go of them and enter into the cynical and destructive doings of the real world, as personified by Brinker, and the war (Chapter 6).