Marple and the concept of human similarity

Like every fictional detective, Miss Marple has her own characteristic modus operandi applied to the solving of cases. This happens to be the slotting of people by their resemblance (in behaviour) to others previously known to the old spinster. Since there is a strong autobiographical influence in almost all Agatha Christie's stories, it is fair to assume that the Dame believed strongly in this theory and applied it herself.

Essentially, the premise is that someone's temperament or behaviour reminds you of another from your experience and you then predict the unknown sides of this new person based on what you know of the original. Miss Marple of course has a high rate of success at this, and probably that's why her stories are quite boring or monotonous.

Anyway, can this theory be practised in real life? Sometimes, it does seem possible. Sometimes, I meet people who remind me of others in their mannerisms, speech patterns and reactions. Though I don't remember if this is true of all cases, but there are a few startling "coincidences" where predictions of behaviour based on previous empirical data matched future actions of these fellows. Wonder if the world is indeed partitioned into such sets.

P.S for BC junta: any T&T comments on this post will be mercilessly censored :-)