"Sorry bud, it's true. On average, right wing people are much dumber than left wing people. Religious people are dumber than non-religious people, too, on average. Religious people are also more likely to be right wingers."

Not at all true. There's plenty of religious people on the left. They just worship the State.

There are a couple interesting statistics in this regard.

Left wingers have a 2 pt IQ advantages over right wingers on average. However, if you only look at non-religious left wingers vs non religious right wingers. The non religious right has a 5pt IQ advantage on average.

Edit: i can't find the source for the religious thing. However a 2014 study has revealed that:

Comparing strong Republicans with strong Democrats, Carl finds that Republicans have a 5.48 IQ point advantage over Democrats.

https://reason.com/archives/2014/06/13/are-conservatives-dumber-than-liberals