Why was Reiko "disposed of"? In Shinsekai Yori (From the New World), children who show the potential to become either Akkis (fiends/ogres) or Gouma (karma demons) are killed off and removed from society.

Examples:


   
 Katayama Manabu - He cheats in the ball tournament and is disposed of near the end of episode 2.
 Aonuma Shun - He becomes a karma demon and dies after episode 10.
 Kutegawa Izumi - She becomes a karma demon and is told to commit suicide in Tomiko's dialogue in episode 12.
 




But what about Amano Reiko?

She "disappears" at the end of episode 1. But what did she do wrong? It was apparent that she wasn't skilled with her juryoku (psychic power or Cantus). But is that reason enough to kill her off?
I will use the manga to answer this question. There are quite a lot of differences in the plot between the manga and the anime. However, the truth about the history of mankind, how the human population is reduced and consists of only Cantus users, and the checks and controls employed to prevent Cantus (Juryoku - 呪力) users from killing each other are essentially the same.



From the statement above, it seems that those who cannot control their Cantus well may unconsciously cause collateral damage. Although there is no example in the anime/manga, I guess that it is analogous to a shaky hand operating a water tap: the water tap itself is not broken, but the poor control causes the water (analogous to Cantus) to flow out much more or much less than necessary.

This is different from the case of Hashimoto-Appelbaum syndrome - Karma Demon (Gouma), where a faulty running water tap would make a good analogy of: the water just keeps running out without effective way to control the amount, like the Cantus power of a Karma Demon is constantly leaking to his/her surrounding subconsciously without any way of stopping. As seen in the anime, Shun can only redirect his Cantus to orbit the balls, but the power leakage cannot be stopped.