"ISTPs are equally difficult to understand in their need for personal space, which in turn has an impact on their relationships with others. They need to be able to “spread out”—both physically and psychologically—which generally implies encroaching to some degree on others, especially if they decide that something of someone else’s is going to become their next project. (They are generally quite comfortable, however, with being treated the same way they treat others—at least in this respect.) But because they need such a lot of flexibility to be as spontaneous as they feel they must be, they tend to become as inflexible as the most rigid J when someone seems to be threatening their lifestyle (although they usually respond with a classic SP rage which is yet another vivid contrast to their “dormant,” impassive, detached mode). These territorial considerations are usually critical in relationships with ISTPs; communication also tends to be a key issue, since they generally express themselves non-verbally. When they do actually verbalize, ISTPs are masters of the one-liner, often showing flashes of humor in the most tense situations; this can result in their being seen as thick-skinned or tasteless."