Handedness bias in Raven's Matrices A few years ago I tried a Raven's Matrices IQ test on the Internet. In every test the bottom right element had to be deduced and this could always be done by scanning the first two rows to determine the pattern. It may also have always have been possible to deduce the solution by scanning the first two columns, although I am not sure that the test designer had this in mind.

It occurred to me that there could be a built-in bias favouring right-handed people or people who first learned to read horizontally from left to right.

It should be fairly simple to devise experiments to test for such bias but an (admittedly rather cursory) Internet search found nothing relevant.

Has there been any such research?
There isn't much of a difference in IQ tests between left and right-handed people. I don't know if this is (more) significant on a sub-test like Raven's.

On the other hand there's  some correlation between both handedness and first-language script direction and the phenomenon of mirror writing. So the native script direction may be relevant to a test like Raven's.  I don't know if they adjust for it (e.g. by rotating the matrix) when it's "translated" to Hebrew or Japanese.