The "laid-back" Performer who coolly and detachedly surveys the world describes the ISTP until...their "button is pushed" and they, with all due speed and gusto, enter the "hands-on" experiencing realm of mechanical devices, race cars and other mechanical vehicles, crisis situations (emergency vehicles), industrial arts, situations requiring facility with numbers or technical data, or emergency situations that require working under pressure.
ISTPs present a paradoxical picture. They appear to be lazy [there's no other word for it!] but they are really energy-conservers: constant activity does not appeal, per se. Nor are they anti-activity. They simply don't believe in getting involved in the "non-essential" or during the "non-essential stage". Of course, they are willing to define "when" that is for themselves or for others but not too willing to have that defined for them. [psst: they can "mind your business" but don't want you to mind theirs!]
They really want to be "free spirits" to decide, to come-and-go as they please and/or set their own boundaries but, in fairness, will also give the same latitude to others. They just don't go for the "organized" thing. "Live and let live".
ISTPs are not "talkers" so communication [of warmth, of joy, of grief, of pain] can become difficult in relationships. They can, however, "zap" you with a brief retort - which can either be so funny as to have you in stitches or silently massaging your ego from the painful barb lobbed your way. And they won't even know that they hurt you in the process for they are not always aware of tender or provocative moments. The "warm-fuzzy" is not their thing.
They are not easy to hurt - but they CAN be hurt. And it is not always easy for them to handle it for the empathetic, supportive role is not natural to them, so they cannot easily support either themselves or others. They are known to select and present very meaningful, insightful and thoughtful gifts - but are embarrassed if a BIG public deal is made over it.
It's not too easy to convince the ISTP of very much to which they do not naturally gravitate as they are highly skeptical persons, not putting too much faith in academia or science. They follow the non-traditional route - freethinkers and doers, shunning the educational route if possible.
Though quiet and unpretentious in demeanor, ISTPs can live dangerously - driving motorcycles, operating heavy equipment, manning emergency vehicles, mountain climbing, using power tools and the like.
They make good companions if it is not necessary to act coy or cute or exhibit social graces and submit to very many "have-to" events or traditions - since they are anti-authoritarian, even when they do not always realize that they are! Non-pressuring, they don't like to be pressured. And that's that.
This concludes our description of the ISTP personality type.
* Personality Type Description used with permission from the author, Fannie R. Linder, Psy.D.