Studies of dolphins, primates and humans show the reason we choose the companions we do is more complex, and perhaps less honorable, than we might think.
“Friendship," wrote CS Lewis, “is born at that moment when one person says to another: ‘What! You, too? Thought I was the only one.’” He wasn't the only one. Plato wrote "similarity begets friendship." in his 360 BCE play Phaedrus. And Aristotle had the same idea when he wrote, "some define it as a matter of similarity; they say that we love those who are like ourselves."