>>I can recall being intrigued by how many of the world’s most brilliant physicists were Hungarian Jews from Budapest.
>>It just about has to be genetics.
And why can’t the ability to acquire knowledge be as much a matter of culture and upbringing as using ones’ hands while speaking, saying “knock wood” for good luck, making a stranger feel welcome, etc.? The Florentine Renaissance, that little romp in a meadow that gave us 3-D rendering for blueprints, machine tool industry, modern astronomy and eventually the Industrial Revolution, happened in Northern Italy because of the creation of surplus value by the merchant class and the translation of lost Greek texts saved by Arab scholars, not by some indwelling knack for numbers. The Florentine Renaissance spawned the Elizabethan Renaissance, the French Enlightenment, the Prussian Education Reforms and, yes, the Philadelphian Renaissance centered around the printing press of Benjamin Franklin and others resulting in our American Revolution. If you are an oppressed minority and wish to survive, you begin to live by your wits and get smart as a culture. Conservatives will soon learn this.
You're right that it can't all be genetics. The Arabs are a Semitic people related to Jews (at least to Sephardic Jews and to the paternal line of Ashkenazim), and there's a world of difference between Arab and Jewish achievement today. Even among Arabs, there's a world of difference in how much Christian Arabs (the Lebanese diaspora) achieve economically and their Muslim "countrymen", especially in immigrant communities. That difference - with the Christians successful merchants and the Muslims mostly poor in Lebanon, is almost certainly cultural.
However, isn't it reasonable to argue that the same pressures (ostracism, oppression) that selected for placing a cultural premium on achievement and education also created a biological pressure for higher intelligence and achievement through natural selection? Not that oppression and minority status always does this - there are plenty of "minority" groups in America and in Europe who aren't exactly known for being high-end achievers.