Don, I did a DuckDuckGo search (thanks Ron) and found this at the Oxford Academic website (long comprehensive article on gout, so only pasted this part on intelligence). Of course, trust the internet at your pleasure.
UA and intelligence
The oldest hypothesis was expressed by Orowan [43], due to the similarity of the structure of UA and some brain stimulants, such as caffeine and theobromine. According to this idea, the loss of uricase activity and the subsequent increase in UA levels could have given rise to a quantitative and qualitative leap in the intellectual capacity of hominids in the evolutionary process. It has been suggested that UA, like other purines, is able to stimulate the cerebral cortex and that the superior intellectual power of higher primates may partly be due to these higher levels of UA [44]. Consistent with this idea is the finding that glutamic acid, which is involved in the endogenous production of UA, seemed to improve cognitive functions when given therapeutically in cases of mental retardation [45].
Several authors have found a significant correlation between UA levels and higher intelligence in children and young adults [46–48] and an association of gout with higher intelligence. Sofaer and Emery [44] studied the presence of gout in highly gifted people, with an intelligence quotient >148, and their families, observing that the prevalence of gout in males with an average age of 36 years was 1.8%, higher than that in the general population aged 58 years (1.5%), and that the prevalence of gout among families of both sexes at a mean age of 34 years was double (0.6%) that of the general population aged 44 years (0.3%). That is to say, the highly gifted people and their families have a higher prevalence of gout at earlier ages than the general population. However, other authors have not seen this association between UA and higher intelligence [49], and the findings observed are difficult to separate from the eating and social habits associated with economic, cultural and intellectual situations.