IQ testing is a business. Psychologists charge up to $1000 for these tests. Although we concur that in theory, the best of the clinical psychologists will probably be able to test IQ with a higher degree of accuracy than group-administered tests (e.g. Mensa offers such tests) or what is available online, the purity of the IQ measurement is easily compromised by the level of subjectivity applied by the assessor. In fact, research has shown that IQ scoring for the same individual on the same test can fluctuate by 8 points depending on the assessor. So there reality is that there is a risk that you can dish out $1k to be told that you have an IQ of 120, which could really be as low as 112, but as high as 128 depending on the competency of the psychologist who is administering the test.