and Teddy was in on it, too?!?

What is WITH these novelists? Apparently Theodore Dreiser, of An American Tragedy and Sister Carrie fame (both very good books, by the way) was also a department-store designer! He is quoted in Coercion as saying:

"[Mannequins] create an atmosphere of reality that aroused enthusiasm and acted in an autosuggestive manner."

I just don't get it - did writers back then also tend to be social psychologists, or did someone for some reason consider them experts on the human mind and his antics just because they had written a good book or two? Odd, very odd...