It is impossible to "explain" something that is a sweeping statement that may or may not be true to the extent you are making it. There are a lot of variables. The biggest mass immigration of Jews was around the turn of the 19th century wasn't it? When we saw a large influx of poor Eastern European Jews. These people were largely poor uneducated "peasants" (ironically, not too different than those fleeing Central America today). But they didn't "make it" in just one or two generations. A good many were born in, lived in and died in the "ghetto". They worked in the garment industry, the created a rich culture in the areas they lived in, with Yiddish news, signs, and Kosher markets. In that sense they aren't much different than other immigrant groups.Like what other variables? Tens of thousands of Jews came in through Ellis Island - poor, uneducated, unable to speak the language, no job, no family connections, and yet….a generation later, their children almost all became educated and affluent.
So what other variables would be involved other than their intelligence and motivation that were NOT available to the population at laege?
The other you ignore is they had help from wealthy Jewish aid organizations that helped "Americanize" them, taught them the customs and language and educated them. Their success was not entirely on their own.
These factors you leave out. I'm not disputing that as a people they have been very successful, but how many never made it out of the ghetto? What if they hadn't had any help?