In order to understand others, one must be able to empathize. In order to empathize, one must learn to understand others. Believing we know all about a person from some superficial external things is a human immaturity that most of us go through in childhood, and many of us don't completely outgrow. But those who have grown to a certain level of maturity, and are able to learn and grasp new information, are aware that they are not fully mature, completely wise, and a fully enlightened, omniscient being, and so can keep maturing and growing. When we ACCEPT that we are humans, and that humans have certain tendencies like making sweeping judgments with little or no information, making huge assumptions, believing our own ego b.s., and trying to dominate other humans just because we share chimpanzee DNA, we can learn how to grow out of these tendencies. Those who can't accept their own creature feature issues are funny, they'll do things like project these issues onto others and deny having them themselves; they'll have magnified domination tendencies BECAUSE of their denial, or they'll try to JUSTIFY their behavior with the excuse of "genetics"; "I can't help the way I was made". Unfortunately for them, using the excuse of "I can't help it" is forfeiting sentience. The definition of Sentience is self-awareness. With self-awareness comes awareness of others. With self-awareness comes self-observation, and the ability to control one's behavior. Creatures who are not self-aware can not control their own behavior beyond their emotional and hormonal reactions, and we don't give them "rights" because of this very reason. A person who can't "help" their own behavior apparently is not a Sentient being, and may not be safe to roam around in society without direct supervision.