ISFPs are adaptable and flexible unless something that matters strongly to them is endangered; then they stop adapting. They care deeply about people but may show it through doing things for others more than through words.
ISFPs tend to be quiet and unassuming, and their warmth, enthusiasm, and playful humor may not be apparent to people who don't know them well. They prefer to observe and support rather than organize situations; they have little wish to dominate.