Recently I’ve been doing a lot of reading about MBTI types. I am incredibly tempted to detail the history of personality typing, but for once I’m going to resist temptation. If anyone reading this actually doesn’t know anything about MBTI types or personality tests, there are plenty of other resources that are just a quick Web search away. How many people have Google, Bing, or their search engine of choice integrated into their browser? But I digress. I don’t claim to be any kind of authority on psychology, but a detailed treatment of the history of psychology and personality types is very much outside the scope of this post.

This Buzzfeed post “What’s your Animal Personality Type?” opens with a useful brief description of the MBTI dichotomies. I was going to start writing more about MBTI, but as I already said, that’s a bit beyond the scope of why I wanted to write this post. I’m not exactly sure why I started reading about MBTI recently, but I do know that when I’ve taken online MBTI quizzes before, I usually scored as an INTJ. I’ve noticed recently (here meaning within approximately the last 5 years) that I’ve also started occasionally getting INTP as a result. Maybe it’s all of the reading I’ve been doing on the subject recently, and taking a few unofficial online quizzes, but I currently consider myself to be an INTJ with INTP tendencies.

I’ve seen at least one YouTube video that has said that people get too attached to the four-letter code (e.g., INTJ) without reading about the four functions. The INTJ’s functions are Introverted Intuition (Ni), Extraverted Thinking (Te), Introverted Feeling (Fi), and Extraverted Sensing (Se), while the INTP’s functions are Introverted Thinking (Ti), Extraverted Intuition (Ne), Introverted Sensing (Si), and Extraverted Feeling (Fe). I haven’t done a lot of reading about the different functions yet, but regardless of whether I’m more INTJ or INTP I’m obviously not big on Feeling or Sensing. I think the differences between INTJ and INTP functions are interesting. Ultimately, the differences between INTJ and INTP are probably at least tangentially related to the idea behind this post. The Keirsey Temperament Sorter is similar (if not completely identical) to the MBTI, and calls INTJ “the Mastermind“, while INTP is “the Architect.”

With that out of the way, now to the other half of this post’s title: interpersonal compatibility. More specifically, romantic compatibility. I’ve never had any romantic relationships, which I’m sure this is a surprise considering everything I’ve written so far, and I don’t think I was interested in the idea of dating until I went to college, which probably has some relation to increased personal autonomy and increased availability of intelligent women. I’ve also never been very good at noticing flirting, and generally speaking I’ve had to have someone else inform me that I was being flirted with after the fact. I’d like to think that I might actually notice  if someone flirted with me now, but that would probably require having an active social life instead of sitting in front of my computer, which would in turn require a different work schedule. Anyway, when I was reading about compatibility of MBTI types last weekend, I thought it was interesting to find several different theories. I suppose this only makes sense, though – as I was thinking earlier today, when I was planning on writing this post, biology is messy, and interpersonal compatibility is, to my knowledge, still very much one of those things that we don’t know for certain. As far as we know, we aren’t characters in a computer game programmed with specific traits to follow a specific equation, so opposites don’t always attract and birds of a feather don’t always flock together.

Among the things I think are interesting about MBTI types and different websites is the different estimates for how common they are. INTJs are supposed to be at least one of, if not the, rarest types in the population, and I’ve seen estimates that INTJs seem to number between 1 and 4% of the population. Female INTJs are supposed to be especially rare, apparently.

One site I found cited a couple books on the subject, and said that the best types for a relationship with an INTJ are the ESTJ, INTJ, ISTP, and ENTJ, while a relationship would be possible between an INTJ and a INTP, INFJ, INFP, or ENFP, while the least likely relationship would be between an INTJ and ESFJ, ISFJ, ESTP, ESFP, ISFP, ENTP, INFP, and ENFJ.
The same site said that the best types for a relationship with an INTP are the ENTP, INTP, and INTJ, while a relationship would be possible between an INTP and the ESTJ, ISTJ, ESTP, ENTJ, ENFJ, INFJ, ENFP, and INFP and least likely between the INTP and an ESFJ, ISFJ, ISTP, ESFP, and ISFP.

Another blog I found listed a few different compatibility theories, which I’ll attempt to summarize.
The identical types theory is basically that each type is most compatible with itself, and least compatible with its opposite.
Ergo, INTJs are least compatible with ESFP, and INTP is least compatible with ESFJ.
The opposite types theory is the inverse, and says “opposites attract”, so INTJ and ESFP are most compatible, while INTP and ESFJ are, as you can probably guess, most compatible.
The main cognitive function compatibility theory says that types with the opposite main cognitive function are most compatible. Therefore, INTJ (Ni) is most compatible with ENTP and ENFP, while INTP is most compatible with ENTJ and ESTJ. The secondary function compatibility theory focuses on how the 2nd function of each partner is balanced by the relationship, so INTJ is most compatible with ENTJ, ESTJ, and ENFJ and least compatible with ISFP, INFP, and ISTP, while INTP according to this theory is most compatible with ENTP, ENFP, and ESTP and least compatible with ISTJ, ISFJ, and INFJ.

Compatibility based on tandem processes is based on opposite cognitive functions working together “to create psychological dynamic and balance. There are four pairs of tandem functions: Ne ↔ Si, Se ↔ Ni, Te ↔ Fi, Fe ↔ Ti. According to Keirsey, types who share tandem processes are more likely to get along well and find common grounds for understanding each other.” Keirsey also decided that the S/N (Sensing or Intuition) process had to be shared in this tandem process theory. According to this model, INTJs are most compatible with INTJ (surprise!), ENTJ, INFP, and ENFP, while INTPs are most compatible with INTP (surprise! again!), ENTP, INFJ, and ENFJ. Duniho’s compatibility model is the same as the tandem process theory, except he suggested that the E/I preference had to be the same, which would make INTJs most compatible with INTJ and INFP and INTPs most compatible with INTP and INFJ.

The Love Types model, based on a book titled “Love Types” by Alexander Avila that includes its very own dating website, is an interesting contrast to most of these other models in that it has different compatibilities for men and women of a specific type.
According to this Dr. Avila, INTJ men are most compatible with INTJ and INTP, while INTJ women are most compatible with INTJ and ESTJ (“provided the ESTJ is not a very strong Sensor”). INTP men are most compatible with INFJ, while INTP women are supposedly most compatible with INTJ, ENTJ, and ENTP.

Since 1200-odd words seems long enough for now, I’ll write an additional post later to cover a few incompatibility theories. Maybe I’ll even have feedback!