Type of being is probably the first characterization tool you would think of when looking at a book with aliens. After all, whether someone is human or alien tells us a lot about which side of the war that someone is on. Humans are, well, whatever humans are – squishy? Bipedal? And the Martians are smarter and more advanced. And…
Well, if you've read about the Martians in our "Characters" section you know that for all their differences, Martians and humans have a lot in common. For instance, although the Martians don't have the wheel, both humans and Martians use technology. And even though the Martians inject blood whereas people eat meat, both Martians and humans have a way of disregarding the feelings of those creatures they think of as lesser. Perhaps most tellingly, both Martians and humans kill humans. For instance, in Book 1, Chapters 5 and 6, we get the parallel stories. One is about how the Martians used their Heat-Ray to kill people, the other about how when the people tried to get away from the Martians, they ended up trampling and killing other people.
So, as a clue for characterization, type of being only takes us a little way. Oh, if only we had some other characterization clues.
Luckily, there are at least two big clues that can help us differentiate between characters. (Which is especially useful since there are so few characters with names; we need something to tell them apart.) One of the biggest clues is how the people act, and this is especially interesting since the people are confronted with a disaster.
For instance, the narrator spends most of his time observing and thinking about the Martian invasion. That makes sense. Since he's a scientifically-minded guy, he's going to spend his time thinking about the science of it all. By contrast, the narrator's brother charges into a fight in order to save two women, so we know he's probably more likely to act than to think through a situation. And this nearly gets him into trouble with the robbers (1.16). Luckily for him, one of the two women that he saves is also very active, and she comes back and saves him.
Now, we wouldn't necessarily want to say that anyone in this novel is squarely a hero or a villain. But some of their actions can seem more heroic or villainous, and can help guide our readings. For example, when we read, we really want the brother to get through OK, because he seems like a heroic guy. On the other hand, when the narrator hits the curate over the head with the handle of a meat cleaver, well, we feel a little bad for the guy – he is, after all, under incredible stress. But we also are creeped out by him.
Basically, the way that people act in response to the Martian invasion is a big clue as to how we should feel about them.
The other big characterization clue is how characters speak and what they talk about. Perhaps the clearest examples here would be the curate and the artilleryman. Both of these characters talk a fair amount (especially the artilleryman, who is surprisingly chatty), and both of their dialogues tell us quite a bit about them. The curate uses a lot of Biblical-sounding language and references, such as comparing the destruction around him to the destruction of Sodom and Gomorrah (1.13.15). Meanwhile, the artilleryman speaks less formally – he uses "ain't" and drops the "h" from words like there's no tomorrow. (Then again, maybe there isn't.)
There's also a lot of variation in the speech of the minor characters. For instance, Mrs. Elphinstone doesn't say very much because she's freaking out. Mostly she just calls for her husband, George. However, her sister-in-law is quite a bit more practical and to the point.
One more example would be the group of sappers the narrator speaks to in Book 1, Chapter 9. They speak with a wide range of accents, which might tell us where they were from (if we could understand British accents, which – oh, the shame – we do not) or what sort of social class they belonged to. Now, we're not sure about that, but it seems like they would all be middle or lower class with those accents; anyone who was a higher class would speak a little bit more like Ogilvy or Stent… so perhaps their dialogue can tell us their class.
Food is a big issue in the novel: the Martians subsist on blood, which has a whole set of possible meanings (blood might be considered unclean, or very intimate, or very religious in a Christian sense); the artilleryman wants to live off of canned foods and scraps, which certainly casts his survivalism in a curious light (since he couldn't survive by himself); and the curate is unable to stop himself from eating. We could go on, but you get the idea. It might be very interesting to compare the different foods the people eat.