This article at VOX points out numerous problems with the test. Erika Price, a friend of mine who has a Ph.D in psychology (and who has written articles for this website), summed up the criticisms as follows:
-Myers-Briggs is based on an old, fringe, untested hypothesis
-The categories do not naturally occur in any sample data
-The test itself was formulated by people with no psychometric training or experience
– It divides people into categories when really every trait is a spectrum
– People are divided into binary categories even though most people are near the middle of the spectrum.
-Individuals do not consistently get the same type. (i.e. it is unreliable)
– It does not predict behavior
-It is not used in mainstream psychological research
The article itself concludes:
It’s 2014. Thousands of professional psychologists have evaluated the century-old Myers-Briggs, found it to be inaccurate and arbitrary, and devised better systems for evaluating personality. Let’s stop using this outdated measure — which has about as much scientific validity as your astrological sign — and move on to something else.