Final answer:
John best fits Holland's Investigative personality type due to his orientation toward the theoretical and abstract, his solitary nature, and his mathematics career.
Step-by-step explanation:
John fits Holland's Investigative personality type. This is because he is described as being oriented toward the theoretical and abstract, suggesting a penchant for critical thinking and analysis typically associated with the Investigative type. Holland's personality types classify individuals based on their career interests and personalities, and the Investigative type is characterized by a preference for working with ideas and data rather than with people or physical activities.
John's career in mathematics also points toward the Investigative type, as it involves systematic investigation of nature, phenomena, and theoretical abstraction. As Holland's model suggests, those with Investigative personalities often pursue careers in science, technology, engineering, and mathematics.
Holland's model is used in career counseling to help individuals find careers that match their interests and personalities. John's preference for solitary work and his lack of interest in social interactions further support his classification as Investigative. Given that John is not particularly good with people and prefers to work alone, this reinforces the typical characteristics of the Investigative personality type over the others, such as Realistic, Artistic, or Conventional.