There are some oddly human characteristics of Roger, though, and these present themselves at different times. For instance, when Hester and Roger talk as Hester is in jail early in the book, they have a remarkably civil conversation, where they honestly describe their loveless marraige. While Roger does indicate that he will try to find out who the real father is, and it's obviously for nefarious purposes, he is civil and respectful with Hester. He even gets indignant when she thinks, in her half-crazed state, that he might actually be trying to harm Pearl. In that way, I think, Roger isn't as bad as we might first think.
The best example, though, of Roger being human is how he treats Pearl after death; he leaves his estate to her, something that is certainly unusual compared to how he has acted previously, but demonstrates that he might have had a heart after all.