Any ideas on how to parse that sentence? Probably 'differences' is subject to 'affect', but difficult to tell. On the talk page someone notes that the introduction is messy, and is possibly the result "of different editors putting in different bits of information", but "there also errors in grammar and style". Perhaps that is it.
The principle of linguistic relativity is the idea that differences in the
way languages encode cultural and cognitive categories affect the way people
think, so that speakers of different languages will tend to think and behave
differently depending on the language they use.