Wait, “Wild Swans” or “Black Swan Green”?

I’d like to plot all his novels from before he had his son and after and see if I can recognize any changes in his writing. Like Utopia seems so different from his other stuff (although maybe it’s more along the ones I haven’t read yet), I wonder if becoming a dad, especially to a special needs boy, made him want to write something more hopeful (? I’m not sure if that’s the right word, but less dark).