Why are Jews usually the smartest group of people?

It's frequently the case, but not always. What is in their culture, values and their upbringing? Their wisdom? Look at Mark Zuckerberg. No other group went through more obstacles (and yes, even more than native indians) and yet no other group contributed more to world society. Have you seen the nobel prize winning list? Now, of course Jews aren't automatically smarter than anyone else, Everyone is created equal. "So what's their secret?" -mark twain