Seems like a very crude division of personalities.
Almost everyone in Western society has non-stop raised stress levels and would therefore be a type A.
Yet not everyone fits the rest of that description.
It's like dividing people in good people and bad people. It doesn't work that way. Lot of blends and grey areas.
The same / similar things are written about the myers briggs personality classification tests...
Even though there's more than a few classes (16 blends)...
"MBTI has been criticized as a pseudoscience and does not tend to be widely endorsed by psychologists or other researchers in the field.
There is little scientific evidence for the dichotomies as psychometric assessment research fails to support the concept of a type, but rather shows that most people lie near the middle of a continuous curve.
The scales show relatively weak validity as the psychological types created by Carl Jung were not based on any controlled studies and many of the studies that endorse MBTI are methodologically weak or unscientific.
Test-retest reliability is low (ie: test takers who retake the test often test as a different type)
The terminology of the MBTI is incomprehensive and vague, allowing any kind of behavior to fit any personality type."
Source: simply psychology website
