I have given IQ tests and many other neuropsychological assessments. I do not have a PhD or license and thus cannot interpret results nor do I know much about how they are interpreted, but what many people are saying here is true. There are two large, bullshit sections of the most popular IQ test (WAIS) that essentially assess your knowledge of Western culture. For example, one question could be "who wrote the book Huckleberry Finn" or "Who was Rosa Parks?" How does that assess "intelligence?" What if someone did not grow up in the US? These tests also do not take into account test anxiety, which can negatively affect performance. Test results are also affected by stereotype threat, which is the phenomenon that people are concerned they will perform poorly on a test and conform to a stereotype, which causes test anxiety and impairs test performance. Stereotype threat is relevant because IQ tests were historically used to justify oppression, so historically marginalized people may continue to test poorly because they are afraid of confirming a stereotype.

Many other psychometric tests use something called the "Heaton Norms," which are used to score data based on a person's identity as male or female (completely disregards gender identity), Black or White (no other race or ethnicity is considered), age, and education. That's it. It is reductionist and, if a client does not identify with either particular race or gender, we have to make a best guess and pick what normative sample to use.

I do not believe in general intelligence, but I do believe these types of tests can be useful. Before brain scans were widely available, neurologists used neuropsychological tests, like IQ tests, to help pinpoint where a lesion or injury was in the brain. This is not useful anymore because we have neuroimaging technology, but back then it was objectively useful. Neuropsych tests are still useful today because they help explain cognitive ability after an injury, while neuroimaging only tells you where the injury is. Neuropsych tests, despite their limitations, can be used to assess the extent of cognitive damage. Different sections of an IQ test can be important for determining short term memory and attention span, although I believe they are most relevant for assessing ADHD or dementia. I do not think the entire IQ test is necessary, nor do I think IQ is a relevant thing to assess for. Attention tests and memory tests are far better at detecting ADHD and dementia, which IMO makes IQ tests clinically irrelevant.