It looks fine to me except that I don't know what you mean by working memory. Is it a technical term used in psychology? If you just mean that people who have good memories tend to also have higher IQ scores (in English it is that way round because it stands for Intelligence Quotient) then I would replace "working memory" by "memory use" or simply "good memories".
Thank you. Indeed it is a technical term used in psychology and neuroscience.
Bus the phrase does not sound very elegant to me. Is that the case or is it just me? I am not a native speaker.
The passive structure may look unusual, but it is normal in English. An object is promoted to subject, just as in a simpler passive:
People have observed working memory to correlate with IQ scores. [object of active] Working memory has been observed __ to correlate with IQ scores. [subject of passive]