You see? Now we're having an intellectual debate, this is far more interesting than the stuff you were posting earlier.
While I understand your point in regards to lack of optimism as such traits were emitted by many if not all philosophers. As far as intelligence goes, no. It's not directly measurable but an interesting allegory(Which I HIGHLY encourage reading if you haven't) is the 'Allegory of the cave' by Plato.
The point of this allegory was present and prove to the Sophists that true and pure knowledge exists. Plato divides knowledge in two different sections which are strongly linked to each other, meta-physics and epistemology. Meta-physics is the world around us, epistemology is the knowledge and recollection of the world around us. We're divided into two realms, realm of the senses(The world itself) and realm of the intellect(Forms) which brings me back to your point. Intelligence cannot be measured but still does exists, to be purely intellectual or not to be. I don't want to explain the whole divided line as it's so interesting just reading it yourself, in short words each realm is divided in two division, each of those divisions is then divided into another two. Watch the allegory of the cave and you'll understand it.
Also you're wrong when saying happiness is a subjective emotion which is the whole point of "The republic" and the example Plato displays in that dialogue presents this very well. Basically put, feeling happy DOES NOT mean being happy. To be happy one must live a moral and good life by nature and not by convention.
To give you a very basic example of a happy person is someone who would not steal from someone else EVEN IF they know they won't be caught or face any consequences.
Here, watch this :
This displays the realm of the sense and the realm of the intellect that I mentioned earlier