In The Life of Pi, by Yann Martel, there are two specific instances that i think reveal the complexity of human relationships.
First, while Pi is lost at sea, he and the tiger meet up with another castaway. This man attempts to kill Pi, and the tiger, Richard Parker, kills the castaway and eats him, instead. Even though the man tried to kill Pi, he is saddened by the man’s death. In terms of human relationships, there are several aspects of the complexities here: first, Pi feels badly for the man who tried to kill him. Secondly, as both are lost at sea, would it not have made more sense that Pi and the man work together, thereby improving their chances at survival. In each case, what I would expect to happen is the opposite of what happens.
The second incident occurs at the end of the story. When representatives of the company owning the sunken Japanese ship called Tsintsum come looking for an understanding as whey the ship sank, they do not believe Pi’s story involving the tiger. So Pi makes up a story about being captured, and a man who cannibalized his mother and a crippled sailor. He leaves the men as they struggle with which story to believe. It would seem to me that the very fact that Pi survived the ordeal at all would make the story fantastic but not impossible. Within the complexities of human nature, we find that people do not react as we would expect: they are not always trustworthy, and at times, they are too cynical or too hardwired for “normalcy” that they cannot think outside of the box.