In Never Let Me Go, how might Ruth's social behavior at Hailsham and later at the cottages, be explained?Why is she so eager to seek her "possible"?

Ruth, as her name suggests, has a ruthless quality that
drives her to behave in self-centered ways. Her understanding of her fate is driven by
strong feelings of self-preservation, and she is willing to manipulate her friends
(seducing Tommy when she knows Cathy loves him, and later telling Cathy she has no
chance with Tommy, for example) and adapt quickly to her surroundings (as when she
imitates the gestures and phrases repeated in an outdated popular television show, for
example) in order to ensure her survival. Seeking her original clone/parent is a way for
her to confirm the uniqueness of her own existence, perhaps to emphasize her desire to
fight to survive, and to justify her often drastic means.