From what I have seen, Jewish culture puts a huge emphasis on studies, doing well in school, getting advanced degrees, and professional achievement. Their families push them or expect them to excel. I saw Jewish students at my college having a huge amount of stress over this. Catholic culture doesn’t emphasize those things.
So if you’re going to use measures like how many Nobel prizes won and how many advanced degrees obtained etc then Jewish people are probably “smarter” by that measure. I think there are a wide variety of ways to measure intelligence, not all of them relating to degrees, achievement or how well one does on a test; my parents were two of the smartest people I ever met and neither one had a college degree and both got mediocre grades in school because they didn’t like school. You won’t see their names on the Nobel Prize list but they knew a lot about how the world worked that they passed on to me, and I found that a lot more valuable than a list of academic credentials.