Jane Loevinger was a very smart lady who studied people's personalities. She wanted to understand how people think, feel, and behave, especially when they grow up from being a child to an adult. She made up a test called the "Loevinger's Sentence Completion Test" and asked people to finish some sentences. These sentences were like puzzles where people had to fill in the blanks with their own words.
For example, one of the sentences might be: "I feel happy when..." and people would fill in the blank with what makes them feel happy. Jane looked at all the answers people gave and noticed some patterns. She realized that people's answers changed as they got older and went through different life experiences.
Jane then made a special chart with different levels to show how people's personality grows and changes as they get older. The chart has ten levels or stages, and each one shows a different way that people think, feel, and behave. When people are younger, they might be at an earlier stage, but as they grow up and learn more, they might move to a higher stage.
So, for example, at the very first stage, people might be very selfish and only think about themselves. But as they grow up and learn to be better people, they might move to a higher stage where they start to care more about other people and the world around them.
In summary, Jane Loevinger was a smart lady who studied people's personalities by making a test called the "Loevinger's Sentence Completion Test" and making a special chart with different levels to show how people's personalities grow and change as they get older.