I cannot provide a definitive answer to which MBTI type is the most naive, as the concept of naivety can be subjective and can vary depending on individual experiences and perspectives. However, based on the information provided in the search results, it seems that NF types (ENFJ, ENFP, INFJ, INFP) are often described as being more naive due to their idealistic and unrealistic views of the world.
ENFJs are described as being childlike and innocent and tend to have a strong sense of optimism, which can sometimes make them appear naive. ENFPs are also known for their idealism and desire to help others, which can sometimes make them appear naive or overly trusting. INFJs are described as being naive and trusting and tend to have difficulty understanding complex concepts or seeing the world in a realistic light. INFPs are also known for their optimism and idealism, which can sometimes make them appear naive or unrealistic.
However, it's important to note that the concept of naivety can be subjective and can vary depending on individual experiences and perspectives. It's also important to avoid making generalizations about people based on their personality type, as individuals are unique and cannot be defined solely by their personality type.