"Agatha Christie's characters are stereotypes and caricatures, but they are not just that. They possess not simply two dimensions but two and a half. The little bit of fun gently poked at the "typical" figure, the slightly surprising or contradictory quality, the merest touch of real humanity—all make Christie's types just a bit more than cardboard puppets dancing to the choreography of the plot. In her characterization as in her puzzles, Christie found the perfect balance, the hallmark of the really skilled popular writer, between convention and invention. She gave her readers exactly what they anticipated, yet added just enough that was intriguingly new to keep them stimulated and absorbed."
Robert Barnard's book about Agatha Christie, A Talent to Deceive, remains the best analysis of her. Tbh, the "average best" of Christie contains characterization depth that isn't much different from many modern crime writers.
LoneWolfEkb t1_j1r6est wrote
Reply to The simple greatness of Agatha Christie by -something_something
"Agatha Christie's characters are stereotypes and caricatures, but they are not just that. They possess not simply two dimensions but two and a half. The little bit of fun gently poked at the "typical" figure, the slightly surprising or contradictory quality, the merest touch of real humanity—all make Christie's types just a bit more than cardboard puppets dancing to the choreography of the plot. In her characterization as in her puzzles, Christie found the perfect balance, the hallmark of the really skilled popular writer, between convention and invention. She gave her readers exactly what they anticipated, yet added just enough that was intriguingly new to keep them stimulated and absorbed."
From here: https://core.ac.uk/download/pdf/268163108.pdf
Robert Barnard's book about Agatha Christie, A Talent to Deceive, remains the best analysis of her. Tbh, the "average best" of Christie contains characterization depth that isn't much different from many modern crime writers.