(For Part I, go here)
I first took the Myers Briggs Type Indicator (MBTI) when I was a junior in high school. This was a good time to take it since, like most sixteen-year-olds, I was self-absorbed enough to think I should spend more time trying to figure myself out.
The test labeled me as an ENTP: Extroversion, Intuition, Thinking, Perceiving.
I was a clear extrovert, someone who Jung describes as gaining energy from the world around them, or in my case, trying to set fire to the world around them. Introverts like Jung find energy through reflection. Thinking first, acting second. An interesting idea.
I also tested strongly intuitive, or as the MBTI would observe, I gathered information as concepts and abstract patterns rather than as concrete, immediate facts available to the senses.
One axiom of the MBTI is that personality types are stable, more or less. As this idea goes, the psyche sets up basic patterns of gathering, interpreting, and acting on information quite early, by age three or four.
Yet critics of the MBTI such as Paul Matthews point out that people who take the test often get different answers. My testing history confirms this as well. In high school, the MBTI tagged me as a thinker rather than feeler, deciding issues on logical and consistent premises.
When I took the test again last week, I had swung over to the feeling side of the spectrum, making decisions based upon personal association or empathy more than general principles. That a person’s psychological type seems squishy, mutable over time, is one of many criticisms leveled at the MBTI, one that challenges its claim to measure meaningful psychological differences.
Still, my MBTI evaluation has been stable other than that, particularly in the final category of perceiving/judging which evaluates how people process information. Strongly judging individuals tend to like settling matters and, as a result, gather information in order to make decisions and tie up loose ends.
Those with strong perceiving tendencies (of which I am one) gather information like rodents in November, amassing it without end. Perceivers are the hoarders of ideas, stowing and revising them even though it keeps things unsettled. They have messy desks.
Driving on Rt 6 in Wellfleet last week, my wife Michele (an INFJ) wondered how her students might type characters in her lit courses. Ahab would have to be an INTJ. The Great Gatsby? ESFP I think.
The conversation brought me back to a post I wrote last year about The Explorer Type. At the time, I was thinking about how certain explorers, such as Roy Chapman Andrews and Louis Leakey, took on similar cultural personae: popular outsiders who contributed to, but were not a part of, the academic establishment.
Was there something deeper here? A psychological type that lay behind the public persona? The ENTP personality type (Extrovert, Intuitive, Thinking, Perceiving) is often labeled “The Inventor-Explorer.” Other analyses of Myers-Briggs tag INTP (Introvert, Intuitive, Thinking, Perceving) as the rightful home of this type. Yet what spotty data exists on this subject shows that real explorers, such Chuck Yeager and Alan Shepard, test as ISTPs (Introvert, Sensing, Thinking, Perceiving).
Alan Shepard
Then again, test pilots and astronauts offer a narrow field of explorers. Reading Goethe and ranging over the mountains of South America, would Alexander von Humboldt have been an ISTP? Never. An ENTP if ever there was one.
Nor should the military discipline and technical demands of modern spaceflight necessarily point to controlled, process-oriented types such as ISTPs. The world’s most famous astronaut is a confirmed ENFP.
An ENFP seeks out new worlds.
Take a quick MBTI assessment here.
Type profiles are available here.
Other posts on exploration and personality:
Time to Eat the Dogs 
From one ENTP-to-ENFP convert to another, cheers. (I’ve always wondered what the predominant MBT is among Trekkies…)