How to Analyze People on Sight or How to Analyze People on Sight Through the Science of Human Analysis: The Five Human Types is a 1921 book by Elsie Lincoln Benedict and Ralph Paine Benedict.
I had expected the book to be outdated, but the subject of analyzing people was handled surprisingly maturely given the time that it was written. It makes a full disclosure to inform the reader that this is not meant to be used to judge people. It assures the reader that the statistics used are only the numbers that have been proven consistent. Although I wouldn't say it helped me read other people better, it did help me better understand myself after finishing a self-analysis.