Generalizing from research presented in the text, if a 4-year-old was observed speaking to a 2-year-old, what kind of speech would the 4-year-old be most likely to use:
◦ the same kind of speech he uses when talking to his mother
◦ the same kind of speech he uses when talking to his older brother
◦ the same kind of speech he uses when talking to his preschool teacher
◦ a simpler version of his normal speech