The functional stack of the ISFP:
1) Dominant: Introverted Feeling (Fi) - This is different from Extraverted Feeling (Fe) in that they tend to be more independent. Indeed, they are suspicious of collective opinions and attitudes, and are especially hostile towards what comes off to them as fake or pretentious. Unlike the melodramatic Fe type, the ISFP is more composed and outwardly calm, in some way resembling Ti types.
Like the Te and Ti types, they are also quite intense and deep. As a juging function, this function tends to be serious and grave rather than lighthearted. Their outlook on life is quite serious, and can come off to more lighthearted types as somewhat solemn.
While Se and Fi types areboth sensation-seekers, after a fashion, the ISFP is more deliberate and focused on specific goals when it comes to their sensation seeking, whereas the Se types may be more indiscriminate in their pursuit of pleasure and experience. This intentional and serious attitude distinguishes from other types that may be predisposed towards sensation-seeking.
2) Auxiliary: Extraverted Sensing (Se) - This is what causes a somewhat hedonistic streak in the ISFP. They tend to be preoccupied with novelties surrounding the 5 senses. Unlike IN types, as we note further on, the ISFP is more action-oriented rather than seeking novelty in the form of thought.
They oftentimes enjoy performance-oriented activities or sports. While they are oftentimes artistic in a way comparable to the IN types, their artistic talentis less likely to be literary or abstract, and more likely to have to do with performance-oriented art or the visual arts, or sometimes, with fashion, in accordance with their concreteness-oriented nature. They oftentimes likewise exhibit an adventurous attitude when it comes to trying new foods.
3) Tertiary: Introverted Intuition (Ni) - While they tend to predominantly interested in the concrete or the physical, this function allows them a certain degree of versatility when it comes to abstract or theoretical thinking.
4) Inferior: Extraverted Thinking (Te) - It is this which draws the ISFP unconsciously towards objective values, contrary to their conscious and overt preference for subjectivity. As this function causes them to be oriented towards towards understanding systems and structures, they oftentimes enjoy organizing things for their own sake, oftentimes to an excessive degree that gives them a somewhat obsessive-compulsive personality.
The ISFP, like the INTP, oftentimes tends to lack assertiveness and exhibit tendencies towards conflict-avoidance. This is correlated with a tendency to feel as though they do not have control over the world in which they live.
At around 8-9 percent of the population, the ISFP tends to make a great caregiver or nurturer. An Introverted Feeling (Fi) type, they enjoy expressing their tendency as a lover or nurturer with children or animals. They tend to be highly loyal and devoted. The ISFP tends to be highly action- and concreteness-oriented, as opposed to abstract.
They tend to exhibit unusually good hygiene, and have a developed fashion sense. Many ISFPs tend to be athletic and dexterous. While IN types may be more interested in intellectual pursuits, the ISFP is more interested in physical exploration.
They tend to be independent; a trait typical of IP types. While they may be highly intelligent, they are oftentimes underperforming in academic environments because of their predominant interest in physical exploration rather than more purely intellectual pursuits. Unlike an IN type, they tend to be optimistic, less depressive, and more practical.
Phase I - The Introverted Feeling (Fi) function develops. While they can oftentimes be quite reticent when it comes to expressing themselves, they nonetheless can oftentimes think in a highly polarized manner.
Phase II - Their auxiliary function, Extraverted Sensing (Se) emerges, and the inner novelty-seeker or sensation-seeker comes out. They begin to seek out new adventures and experiences.
Drenth, Dr. A.J. (2014-01-08). The 16 Personality Types: Profiles, Theory, & Type Development (Kindle Locations 84-86). Inquire Books. Kindle Edition.