While two individuals of any type combination can make a relationship work or fail, research conducted on committed couples shows there is a definite trend in the personality types that are drawn to each other, and in the type combinations that last longest in a romantic partnership. At PersonalityPage, we call these types "natural partners."
The natural partners of ISFJ are ESFP and ESTP types. The ISFJ's dominant function of Introverted Sensing pairs naturally with Extraverted Sensing types.
Outside of natural partner pairings, it's especially important for an ISFJ to partner with someone who can respect their need to honor their rich inner library of facts and memories, and their need to nurture the social group in which they live. The dominant Extraverted Intuitive types ENFP and ENTP might find it difficult to understand or respect the ISFJ's lack of interest in the possibilities that exist in the world, and the ISFJ may find the Extraverted Intuitive irresponsible and impractical. To a lesser degree, the dominant Introverted Intuitive types (INFJ and INTJ) might also present a challenge to the ISFJ, but Introverts can often respect the individual nature of each other's inner worlds, however different they may be. The shadow type for an ISFJ is ENTP. This type pairing is typically challenging.
The Intuition/Sensing preference is a special case in relating—strongly expressed Intuitives relate better to other Intuitives, and strongly expressed Sensers related better to other Sensers.
How did we arrive at the conclusion that ISFJs are the natural partners of ESFPs and ESTPs? Through empirical evidence, research, and a thorough understanding of the sixteen personality types and the personality functions that drive them.
In Jungian terms, personality "functions" refer to the four core traits: Intuition (N), Sensing (S), Feeling (F), and Thinking (T). The term "attitude" refers to the direction of the function, i.e. Introverted (I) or Extraverted (E). The ISFJ has a dominant function of Introverted Sensing, a secondary function of Extraverted Feeling, and a Judging orientation toward the external world.
Our natural attraction to people who share our dominant function, but who use it in a different direction works very well for us. We not only flip-flop the Introverted or Extraverted trait, but we also flip-flop the Judging or Perceiving trait. In this way, the partner that we choose for ourselves will have a very different approach to dealing with the world. If we are laid-back and indecisive, our partner will be structured and decisive. If we are reserved, our partner will be outgoing. Natural partners complement each other, and challenge each other in healthy ways. But for all of their apparent differences, natural partners share the same dominant function, which instills them with similar ideas about what's truly important in life. They will experience a feeling of being on the same level.
Of course there are many things that influence a relationship's success or failure, such as family background and intelligence. Recent research shows that the number one cause of long-term success for a couple is that they treat each other with respect and kindness.
Although we believe firmly that this model works well to help in finding and maintaining healthy relationships, it is important to remember that it's just a tool. We offer guidelines to help you understand the kinds of things that you value in a relationship, rather than guidelines that you need to follow strictly. It's important to remember that there's no such thing as an effortless romantic partnership. But undoubtedly, some are easier than others.