If one of your MBTI letters is borderline, your answers on that scale landed near the middle, and either letter could come out on another day. You are not half a person or an undecided one. You sit between two poles that both read as you, and an honest result shows both sides instead of picking one for you.
What “near the middle” means
Each letter is one end of a scale. E and I are the two ends of the People scale, Outgoing and Reserved. Your answers put you somewhere along that line, and the letter says which side of the middle you landed on. Most people land clearly on one side. Some land close enough to the middle that the side is a coin toss.
A borderline letter is not a weak answer. It usually means both descriptions fit you in different settings: you think out loud with close friends and go quiet in a crowd, or you want a plan for work and none for the weekend. Both poles are written in positive words for a reason. Neither is better, and sitting between them is a real place to be.
Why forcing a side makes results flip
A test that always prints a letter has to pick a side even when you are a hair from the middle. Take it again, a few answers shift by one notch, the letter flips, and the type flips with it. You read INFJ on Monday and INFP on Friday and wonder which one is the lie. Neither. The scale was close and the format hid it.
We checked how often this happens on 60,000 real answer sheets drawn from the same Johnson IPIP-NEO data as the reference group of more than 135,000 people. Each scale got two equivalent sets of research statements, and we counted how often the same person landed on the same side in both.
- With this test’s format, about 81% of people get the same letter on a scale in both sets (estimated).
- A 20-question yes-or-no format comes out around 65%.
- Every extra letter multiplies the chance of a flip. Across all six letters, only 28% of people get the exact same six in both sets.
That is the honest cost of any letter type, and it is why letters near the middle need a different treatment. More on the numbers in how accurate is an MBTI test and how many questions a test needs.
How this test shows it
When a scale lands close, the test first asks you a few more statements on that scale. If it is still close after them, the closeness is part of your answers, not a slip on one statement.
The result then says so in three places.
- On the scale, the label reads “In between” instead of a letter, with a note: “You sit between Outgoing and Reserved. Both read as you.”
- On your result card, that letter in your code carries a wavy underline, so anyone you share it with can see that one letter is held lightly.
- Under “Why you read this way”, you see your own answers that pulled you toward each side.
Shown this way, far fewer results flip. On each scale, only 4–7% of people see a clear letter flip to the clear opposite. Across the four MBTI letters, 82% see no clear flip at all; across all six letters, about 7 in 10. One caveat: both sets were answered in one sitting, so a real retake weeks later agrees somewhat less. How it was measured is on the how it works page.
What to do with an in-between letter
Read both types. If you sit between E and I with NFP settled, read INFP and ENFP and notice which paragraphs you nod at. They are one letter apart, and your result lists the other one under “Nearest types” for exactly this reason. The same goes for the two letters after the dash: between Steady and Sensitive, or between Collaborative and Self-reliant, read the two variants and keep what fits.
Notice when each side shows up. An in-between letter often follows context. Many people are Outgoing in a small group they trust and Reserved in a room of strangers, or Planned on a deadline and Flexible on a free afternoon. Naming the setting is more useful than naming the letter.
Keep it when you retake. People change, and your answers on a close scale will drift. If the letter settles one way in a few months, that is one letter moving, not a new you. The result reports which letters moved, never “your type changed”.
Do not treat it as a flaw. A borderline letter is not indecision or a failure to know yourself. It is the most accurate thing a test can tell you about that scale, and it means you can borrow from both sides on purpose.
If you want the whole picture, the 64 types post explains how the six letters fit together, and the types page lists every one.
MBTI is a registered trademark of The Myers-Briggs Company; this test is not affiliated with it.
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