I've read several recent posts quibbling with McCloud's assertion that it is easier for readers to identify with cartoon images. While I may not entirely support his viewpoint myself, I do think he does a fair bit more justification of this claim than has thus far been acknowledged on the blogosphere.
McCloud explains cartoons as "a form of amplification through simplification" (30). In his mind the cartoon trades visual realism for conceptual resonance. Realistic details are potentially distracting, and in their absence the audience is able to focus on the distilled concepts highlighted by the cartoon style. This distinction is echoed by his proposal of the separation of human experience into two categories: the realm of the concept and the realm of the senses (39). Our identities, according to McCloud,"belong permanently to the conceptual world" (40). We identify more with cartoons because they appeal more directly and efficiently to our sense of identity on it's own turf, if you will, in the conceptual realm. Our sense of our selves is conceptual, McCloud points out. When we are aware of our own faces, it is not in their full detail, rather we have a concept of them "a sketchy arrangement...a sense of shape...a sense of general placement" (36). This does not mean that we must always identify with cartoon figures, but rather that their design lends itself to this possibility if we are so inclined.