But that's the problem with these students as well: their intuition tells them that when it's warmer the sun has to be nearer. the fact that the amount of sunlight throughout the day (timespan) causes warmer seasons is an indirection in thinking.

Of course they should know what causes seasons if they had payed attention in class.

I wonder how they reacted if you'd ask them about the hemispherical difference in summer/winter, e.g. how can the southern hemisphere have winter when the whole earth is nearer to the sun...

apologies: I was watching the YouTube video that's in the bottom of this article, where graduates were asked "what causes summer and winter" that's what my comment above is about!.

My guess is that they see the world in a black and white where things are either 100% safe or 100% dangerous. Where theories are either 100% proven or 100% disproven.

Most people don't. I think many simple things in probability are surprisingly unintuitive.