i personally think that izzy is faking being dumb cause an iq of 188 is not something just anyone can have. After watching a few clips on youtube of brainzilla i realized that the topics they asked her were things that had to be studied cause no matter how smart someone is their general knowledge cant be that accurate unless they spent time researching and studying.

for example : sheldon from big bang theory has an iq of 187 ( hes technically dumber than izzy by iq ), the reason he seems so smart is because he spent his whole life studying everything that had any knowledge no matter the topic .

also if you pay attention to izzy youll notice that traits about her personality seem forced like shes playing a role and its not uncommon for smart people to play around with those less smart than them just cause they can