Below are some membership stats for Personality Cafe and Typology Central. For each type, the first percentage is the percentage of that type at the forum, the second percentage (in parentheses) is the estimated "general population" percentage from the official MBTI folks (from
this page), and the final number on the right is the self-selection ratio for that type — i.e., the ratio of the forum percentage to the general population percentage.
November 2014 membership stats for Personality Café:
INFJ — 9133 — 15.7% (1.5%) — ssr: 10.5
INTJ — 7307 — 12.6% (2.1%) — ssr: 6.0
INFP — 11865 — 20.4% (4.4%) — ssr: 4.6
INTP — 7825 — 13.5% (3.3%) — ssr: 4.1
ENTP — 3709 — 6.4% (3.2%) — ssr: 2.0
ENTJ — 1681 — 2.9% (1.8%) — ssr: 1.6
ENFJ — 1904 — 3.3% (2.5%) — ssr: 1.3
ENFP — 4915 — 8.5% (8.1%) — ssr: 1.0
ISTP — 1926 — 3.3% (5.4%) — ssr: 0.6
ISFP — 1986 — 3.4% (8.8%) — ssr: 0.4
ISTJ — 2094 — 3.6% (11.6%) — ssr: 0.3
ESTP — 635 — 1.1% (4.3%) — ssr: 0.3
ISFJ — 1374 — 2.4% (13.8%) — ssr: 0.2
ESFP — 620 — 1.1% (8.5%) — ssr: 0.1
ESFJ — 573 — 1.0% (12.3%) — ssr: 0.1
ESTJ — 542 — 0.9% (8.7%) — ssr: 0.1
November 2014 membership stats for Typology Central:
INFJ — 1782 — 16.1% (1.5%) — ssr: 10.7
INTJ — 1437 — 13.0% (2.1%) — ssr: 6.2
INTP — 1958 — 17.7% (3.3%) — ssr: 5.4
INFP — 2016 — 18.2% (4.4%) — ssr: 4.1
ENTP — 781 — 7.0% (3.2%) — ssr: 2.2
ENTJ — 298 — 2.7% (1.8%) — ssr: 1.5
ENFP — 1156 — 10.4% (8.1%) — ssr: 1.3
ENFJ — 321 — 2.9% (2.5%) — ssr: 1.2
ISTP — 304 — 2.7% (5.4%) — ssr: 0.5
ISFP — 256 — 2.3% (8.8%) — ssr: 0.3
ISTJ — 278 — 2.5% (11.6%) — ssr: 0.2
ESTP — 100 — 0.9% (4.3%) — ssr: 0.2
ISFJ — 181 — 1.6% (13.8%) — ssr: 0.1
ESFP — 84 — 0.8% (8.5%) — ssr: 0.1
ESTJ — 74 — 0.7% (8.7%) — ssr: 0.1
ESFJ — 65 — 0.6% (12.3%) — ssr: 0.05
And here someone may object: But reckful, come on. Everybody knows that INs are the folks who freaking
live on the internet, so the fact that there are a lot more of them on any particular website may not say as much as you might otherwise think about their greater affinity for the theme of that website. And to that I'd respond: I don't necessarily disagree with that, but the fact that INs are the folks most inclined to
live on the internet — to the extent that you're right about that — is another piece of strong evidence in favor of viewing the INs as a significant type group.
I'd say the INs are the types best characterized as "born students." They're the types most likely to be found learning something for the sheer joy of learning, and the types most likely to begin their response to "What do you hope to accomplish in your life?" by saying (to quote an INTJ woman at PerC), "I want to learn as much as I can."
The MBTI Manual calls INs the "thoughtful innovators" and says they "are introspective and scholarly. They are interested in knowledge for its own sake, as well as ideas, theory, and depth of understanding. They are the least practical of the types." In
Type Talk, Kroeger & Thuesen note that INs "would rather speculate as to why Rome is burning than actually fight the fire. They are speculative, reflective, introspective, conceptual, and highly abstract in orientation."
I'd say INs are the nerds. INs are the folks who tend to be the most serious about the world of literature and philosophy and the arts, and to take one or more divisions of pop culture
seriously. You might say the INs' church is the library. As already noted, the INs are the folks most likely to more or less live on the internet, and to fail to see much of a significant distinction between the internet and so-called "real life." I think INs tend to be the most independent thinkers, and the most likely to define themselves strongly on the basis of their independent perspectives — not "special snowflake" unique, necessarily, but independently arrived at, and often more minority/subcultural than culturally mainstream.
Jung was an IN, Briggs and Myers were both INs, and Keirsey was an IN. And it sounds to me like most of the predecessor typologists whose theories Jung reviewed in
Psychological Types were fellow INs who I suspect were also, like Jung, partly moved to formulate their "different types" theories by the fact that — like a sizeable percentage of the INs in (I assume) most eras — they felt significantly alienated from the majority of their fellow men.
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As a final, more wonkish, note on the INs...
As I'm always pointing out, Jung spent more of
Psychological Types talking about the things he thought extraverts had in common and introverts had in common than he spent talking about all eight of the functions put together. I'm not really a Beebe fan, but he certainly characterized Jung's perspective accurately when he said:
For Jung the attitude type was the primary thing, and the function type a kind of subsomething that expressed that attitude in a particular way. Accordingly, he organized his general description of the types in terms of the attitudes, describing first "the peculiarities of the basic psychological functions in the extraverted attitude" and then going on to "the peculiarities of the basic psychological functions in the introverted attitude."
In the Foreword to a 1934 edition of
Psychological Types, Jung bemoaned the fact that too many people were inclined to view Chapter X as the essence of the book, and explained that he'd put the eight specific "function-type" descriptions at the end of the book for a reason. He said, "I would therefore recommend the reader who really wants to understand my book to immerse himself first of all in chapters II and V." And Chapters II and V are pretty much all about extraversion vs. introversion, with Chapter V devoted to a long analysis of Spitteler's
Prometheus and Epimetheus — which Jung calls "a poetic work based almost entirely on the type problem," explaining that the conflict at the heart of it "is essentially a struggle between the introverted and extraverted lines of development in one and the same individual, though the poet has embodied it in two independent figures and their typical destinies."
And the central focus on extraversion/introversion, and the things Jung thought
all extraverts and
all introverts tend to have in common, runs through every chapter of
Psychological Types other than Chapter X — the only part of the book with any substantial description of the eight functions. As Jung saw it, the dynamics of the human psyche revolved first and foremost around a single great divide, and that divide involved
two all-important components — namely, introversion/extraversion
and conscious/unconscious.
And here's the thing (for purposes of the present discussion): Jung assigned what's arguably the lion's share of the modern conception of S/N (the concrete/abstract duality) to E/I, with the result that, when Jung looked out at the world and spotted what he thought was a definite "introvert," he was almost assuredly looking at someone who'd be typed IN under the MBTI.
So I think it's fair to say that Jung himself viewed the INs (who he called the "introverts") and ESs (who he called the "extraverts") as the two most significant MBTI subgroups — even though he didn't frame them in those terms.