There is no universal agreement as too, which species of Parrot holds the title of the most intelligent, nor is their firm belief as to which is the best. This likely effected by the individualism between Parrots and their environment in which they grew-up.
That all said, there is a reality that Grey's are commonly included when such awards are offered.
When it comes to 'your' Grey, well of course your Grey is clearly at the top.
Greys are right up there. Some corvids too. But the Kea is really something else. Corvids and greys exhibit this 'afraid of everything until they assure themselves its harmless' and then they will interact. Im sure our grey owners will attest to that. Keas on the other hand relish new things and mob rush to check it out. Yes Corvids solve some pretty complex puzzles but kea will solve the puzzle and figure out how to take the puzzle apart.
im ashamed to say, i dont challenge Enzo on an intellect level. I need to improve on that, she used to do jigsaws and colour (correct spelling ) puzzles too, but again i dont have any such toys, but ill get some..
Where Enzo excels is on an emotional level, she astounds me, over the last year she lets me know how I am feeling, she has often said 'its alright' when ive been down or upset, shes asked for cuddles or 'tickle tickles' when ive needed them, shes looked after me. Thanks Enz....
Im going to get her back in to better and more intelligent play time, definitely.
This will make you laugh, a month or two ago Enzo was goofing around and went on her back which for her is 'lets play' i normally rub my nose on her chest when she does this, but this particular time i did just that but her leg went in my mouth.... now she puts her beak around one of her legs, again, this now means 'lets play'. She's daft, and her parront is even more daft lol