This is a bit old, but I beg to differ!
I myself am ISFP, and I've noticed that there are tendencies in me to flee attention and avoid drawing attention, but it can't really be helped that we are extremely private wanderers. We do tend to live in the moment, and planning is definitely a weakness of ours, but it doesn't mean we don't care! I think it depends on degree of how extroverted we are, because the more extroverted, the more it can be easy to give off fake vibes (this is my way of trying to make sense of what you mean by "like cats").
However, we also have much wholesome care when it comes to people, and we want to be liked. This clashes very much with our natural disposition, so we usually have to be approached first, again and again, and we appreciate it when people do, even though we STILL get the feeling to run away sometimes. It's almost like being a walking contradiction.
We can be quite sensitive and take words to heart, so sometimes we feel slightly threatened with the high demands in human relationships, and turn to animals and children for our child-like love. We ARE secretive and intense, and that's how we feel our emotions, it's VERY hard to be expressive of appreciation where it's due. We feel that compliments are a light and superficial form of maintaining relationships. We're not comfortable receiving them, and don't gush others with them either unless it's the way to save from awkwardness and maintain harmony. We love making people happy, but we are not touchy nor wordy, but if comfortable enough, we'll surrender ourselves to you and hope that you honor that. As I read in another forum for INFPs once, but I thought is very applicable to ISFPs too:
"Its hard especially if you want to keep a good relationship with them. We live and die on being understood, especially when it comes to advice - misunderstand me and I won't give you the opportunity to misunderstand me a second time. Me opening up to you is a privilege I let you indulge in to form a stronger relationship - don't abuse it. "
We are not light hearted. Rather, (speaking for myself), we extremely conscious and aware of our feelings and others, and don't like to stand out, so we try to go with teh flow of things. We'll reflect your moods, personalities, enthusiasm, anything, unless we feel our beliefs or values are threatened.
--for the record, my next closest type is INFP, so maybe that's why I cannot relate with previous descriptions, but I truly believe ISFPs are not what people make them out to be
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