How accurately does 16p represent the MBTI?

This article will compare items from the 16 Personalities test with official MBTI resources in order to evaluate the degree to which 16p makes for a valid MBTI test. PDB users often say that 16p cannot be used as a credible means for determining someone's real MBTI type. This article will attempt to determine the veracity of that claim.

I/E

Introversion

16p: Reluctant to meet new people.
MBTI: I: Reserved, low-key, are introduced, E: Sociable, genial, introduce people
Correlation: Strong

16p: Avoid leadership roles in group settings.
MBTI: E: Join groups, Interactive, Seek spotlight, I: Find individuals, onlooker, seek background
Correlation: Strong

16p: Try not to draw attention to themselves.
MBTI: E: Seek spotlight, I: Seek background
Correlation: Strong

16p: Avoid making phone calls.
MBTI: E: Prefer to communicate by talking, I: Prefer to communicate in writing
Correlation: Strong

16p: Prefer solitary work.
MBTI: I: Prefer space, Enjoy solitude
Correlation: Strong

Extraversion

16p: Regularly make new friends.
MBTI: E: Sociable, genial, broad circle
Correlation: Strong

16p: Strike up conversations with strangers.
MBTI: E: Interactive, want contact. Readily take initiative in work and relationships
Correlation: Strong

16p: Enjoy group activities.
MBTI: E: join groups
Correlation: Strong

16p: Prefer company to solitude.
MBTI: E: Seek popularity, broad circle, join groups, want contact. I: prefer space, enjoy solitude
Correlation: Strong

16p: Not fatigued by social interaction.
MBTI: E: They... receive energy from interacting with people.
Correlation: Strong

16p: Initiates social activities.
MBTI: E: Readily take initiative in work and relationships, introduce people
Correlation: Strong

16p: Prefer busy places to quiet ones.
MBTI: E: Join groups, want contact. I: Seek intimacy, one-on-one, prefer space, enjoy solitude, seek background
Correlation: Moderate

I/E Summary

Similarity score: 96%.
Almost every item is directly echoed by descriptions from official MBTI reports. Only one item "prefer busy places" was strongly suggested but not directly addressed by the MBTI materials. This suggests that 16p Extraversion is a highly reliable indicator of MBTI extraversion, with the caveat (that should be extended to all subsequent judgments) of the briefness of this test.

N/S

Intuition

16p: Interested in a wide variety of topics.
MBTI: N: seek novelty, scholarly, idea-oriented, intellectual, new and unusual
Correlation: Strong

16p: Like books and movies that are open to interpretation.
MBTI: N: Figurative, symbolic, intangible, idea-oriented, intellectual, seek patterns, hypothetical
Correlation: Strong

16p: Ponder the "big questions".
MBTI: N: seeing the big picture,
Correlation: Moderate

16p: Like art museums.
MBTI: N: symbolic, intellectual
Correlation: Weak

16p: Interested in views that conflict with their own.
MBTI: N: seek novelty, idea-oriented, new and unusual. S: Conventional, customary, tried-and-tested
Correlation: Moderate

16p: Intrigued by controversy.
MBTI: N: seek novelty, idea-oriented, unconventional, different, new and unusual
Correlation: Moderate

Sensing/Observing

16p: Uninterested in interpreting and analysing creative work.
MBTI: S: Factual and concrete, Exact facts, literal, tangible.
Correlation: Moderate

16p: Not artistic.
MBTI: S: Focus on what is real and actual, 
Correlation: Weak

16p: Bored by theoretical discussions.
MBTI: S: Factual and concrete, Focus on what is real and actual, Exact facts, literal, tangible, matter-of-fact, results-oriented, applied, Hands-on
Correlation: Strong

16p: Do not ponder the "big questions".
MBTI: S: Oriented to present realities, Factual and concrete, Observe and remember specifics, Conventional
Correlation: Moderate

16p: Uninterested in philosophy.
MBTI: S: Oriented to present realities, Factual and concrete, Focus on what is real and actual, applied, trust experience
Correlation: Moderate

N/S Summary

Similarity score: 55%
The correlations between the two systems are a lot weaker for this spectrum. The biggest weakness seems to be in the realm of artistic interests, 16p suggesting strongly that this is a core component of N/S but the MBTI giving little or no indication of this. However, 16p still scored strongly in identifying interest in abstract and ambiguous topics as being an indicator of Intuition. The correlations between the two systems for abstract thought varied from fairly strong to very strong. 16p N/S is clearly a fairly solid but undeniably flawed indicator of MBTI N/S.

T/F

Thinking

16p: Follow their head rather than their heart.
MBTI: T: Logical, F: Empathetic
Correlation: Moderate

16p: Value rationality over feelings.
MBTI: T: Logical/Reasonable, F: Empathetic, Compassionate
Correlation: Moderate

16p: Find arguments interesting.
MBTI: T: challenging, want discussion, Sceptical, want proof, critique
Correlation: Strong

16p: Impatient with people who are inefficient.
MBTI: T: Firm, tough-minded, ends-oriented
Correlation: Moderate

16p: Struggle to understand the feelings of others.
MBTI: F: Sympathetic
Correlation: Weak

Feeling

16p: Empathic.
MBTI: F: Empathetic
Correlation: Strong

16p: Sentimental.
MBTI: -
Correlation: Weak

16p: Happiest when helping others.
MBTI: F: seek harmony, loyal, trusting, give praise
Correlation: Moderate

16p: Avoid making others look bad.
MBTI: F: loyal, Approving, give praise
Correlation: Moderate

16p: Selfless.
MBTI: F: loyal, want harmony, 
Correlation: Weak

T/F Summary

Similarity score: 45%
The two systems seem to be pointing roughly in the same direction but the direct similarities are rare. Items like "find arguments interesting" and "avoid making others look bad" are heavily implied but not directly addressed.

J/P

Judging

16p: Make Backup Plans.
MBTI: J: advance planner, make lists, Plan specific tasks, Make short- and long-term plans
Correlation: Strong

16p: Finish one project before starting another.
MBTI: Systematic, Scheduled, Orderly, steady progress, Plan specific tasks, note subtasks
Correlation: Strong

16p: Like schedules and lists.
MBTI: Scheduled, Organize their lives, Systematic, structured, like firm plans, make lists, Plan specific tasks
Correlation: Strong

16p: Complete chores promptly
MBTI: Try to avoid last-minute stresses, dislike diversions, Motivated by self-discipline, steady progress, find late starts to be stressful
Correlation: Strong

16p: Likes to "get back on track"
MBTI: Systematic, dislike diversions, like firm plans
Correlation: Moderate

16p: Methodical.
MBTI: Methodical
Correlation: Strong

Perceiving/Prospecting

16p: Don't rely on plans and routines
MBTI: Spontaneous, Open-ended, Adapt, change course, Like things loose and open to change, go with the flow, let strategies emerge, adaptable
Correlation: Strong

16p: Do things at the last possible moment.
MBTI: Feel energized by last-minute pressures, Motivated by pressure,
Correlation: Strong

16p: Postpone making decisions.
MBTI: Open-ended, Like things loose and open to change, let strategies emerge
Correlation: Moderate

16p: Spontaneous rather than consistent.
MBTI: Spontaneous. Adapt, change course, welcome diversions, go with the flow, make flexible plans, bursts and spurts, Want variety, enjoy the unexpected
Correlation: Strong

16p: Struggle with deadlines
MBTI: early start unstimulating
Correlation: Weak

J/P Summary

Similarity score: 91%
Most of these items either refer directly to the same trait across these two systems or they strongly indicate the same general tendencies and leave no doubt as to the overall trait that is being indicated. The only weakness occurs when 16p suggests that P users struggle with deadlines, whereas the MBTI describes traits that would surely predict deadline issues but offers no indication that P users necessarily have this issue.

Summary

Here, again, are the similarity scores calculated by this analysis:
I/E: 96%
N/S: 55%
T/F: 45%
J/P: 91%

In conclusion, 16p scores should be regarded as a strong and reliable indicator of an individual's 1st and 4th letters, but not of their 2nd or 3rd letters. If, for example, some celebrity takes a test and gets INFJ, with strong scores for I and J, then it is reasonable to assert that this person is almost certainly an IXXJ but not reasonable to assert that they cannot be ISFJ, INTJ or ISTJ, purely on the basis of this result. This only applies for strong scores. It is worth remembering that a 40-60% score on any test does not strongly indicate any preference for the given MBTI trait. A person who scores in the 40-60% range for all 4 letters is about equally likely to be any type, but a person who has an extreme score for E and P on 16p, would almost certainly receive an EXXP result from an official MBTI test.

Sources:
MBTI Step II Interpretive Report (themyersbriggs.com)
MBTI_Personal_Impact_Report_Verification_English.pdf (themyersbriggs.com)
Is 16personalities.com... | Wiki - Personality Database (personality-database.com)