In 2015, the journal Mankind Quarterly published a study called The Intelligence of Ashkenazi and Sephardi Jews in Serbia by Richard Lynn and Jelena Čvorović.

The authors write:

They shouldn’t mix individually tested people with group-tested people since the latter score higher on the Raven.

They write:

An average IQ of 104 (white norms) is much lower than the 110 IQ Ashkenazim score in the United States, but considering Serbia has an average IQ of 90, it is quite high for that environment. And given how well integrated the Ashkenazim and Sephardim are in Serbia, even the self-identified Ashkenazim might be somewhat mixed.