The thermometer as we know it didn't exist until the 17th century! Although the Chinese seems to have measured temperature with clay pots since at least the 6th century.

The concept of an innate ability to be smart, however, is something else entirely. It is at best a question "I know it when I see it", but where two observers seldom agree.

Compare the concept of "love". It is also an age old idea, a word that exists in all languages and used in conversation every day, but the vain of trying to get observers to agree on it has rightly been a trope for millennia.

The similarities doesn't end there, with books and courses being peddled on the subject of quantifying and scoring it. Very few of these have any scientific ambitions to speak of however, even among the most grandiose of claims.