Psycholinguistic reasons for keeping Chinese characters in Korean and Japanese

The three languages of East Asia - Chinese, Korean, and Japanese - differ substantially, and yet all three use Chinese characters. They use characters similarly in some ways and differently in others. Wherever it is used, a Chinese character is a logograph that represents primarily the meaning: and secondarily the sound of a morpheme. In a Chinese text, all kinds of words are written in characters, whereas in a Korean or Japanese text, characters are used to write Sino-Korean or Sino-Japanese words, which are always content words, while phonetic signs are used to write native grammatical morphemes. Psycholinguistic studies suggest that such a mixed-script text should be easier to read than a single-script text.