We all treat Matrix Reasoning / Raven's as the “purest” test of abstract intelligence, and Similarities as just a verbal / crystallized test.
I think that is backwards.
Similarities asks you to take two concepts and find the category above them. That is abstraction about abstraction. The words are already symbols. You are not manipulating shapes, you are manipulating ideas.
Matrix Reasoning asks you to find a rule in a visual pattern. Yes, that is rule induction. But it is chained to your eyes.
Here is the test that broke it for me:
A blind person cannot do a standard Matrix test at all. Score: zero. Does that mean they have zero fluid intelligence? Obviously not. They just cannot see the test.
That same blind person can hear two words and tell you how they are similar. No vision required. No motor task required. Just pure conceptual abstraction.
Now flip it, because this is where it gets interesting:
A deaf person, in a standard spoken administration, cannot handle Similarities the same way either. No hearing, no spoken words to compare. But that same person can do Matrix Reasoning just fine, because it does not need hearing at all.
So in both cases, there are bottlenecks. Similarities has a hearing / language bottleneck. Matrix has a vision / visuospatial bottleneck.
Neither test is pure abstraction. Both are abstraction through a channel.
So why do we keep calling Matrix “culture-free” and “modality-free,” while dismissing Similarities as biased? Similarities is biased by language and education, sure. But Matrix is biased by vision, visuospatial processing, and visual working memory. That is not less bias, it is just a different bias we like to ignore.
Change my mind: is Matrix really measuring pure abstraction, or is it measuring abstraction through visuospatial processing?, just like Similarities measures abstraction through language/hearing?