Low frequency words: native language vs second language

Question

It is easy to explain why one has better proficiency in common vocabulary in one's native language than in one's second language.

But when it comes to low frequency words, why does the native language still prevail over the second language?

The possibility to see a low frequency word in reading is equally low in both native language and second language, which means the exposure are nearly equal.

And you don't even need to use those words by yourself, which means they are both passive vocabulary in each language.

Why does it seem that we still have a better memory to remember low frequency passive vocabulary in our native language than in the second language? Even if you cannot remember the meaning, we are still likely to give a good guess on the rare word of our mother tongue.

Answer 1

Is the native language better?

In some fields I passively know a lot more specialist vocabulary in English than in Finnish, my native language. This depends on how much I have been exposed to such vocabulary in whichever language.

So in my experience this is domain-specific.

Native language does have some benefits, though

First off, you might have been exposed to all kinds of strange vocabulary as a child. At least in the Western countries I am familiar with, young children's culture is full of things their parents experienced as children, which came from their parents, etc., though of course newer offerings also appear. The adults have much influence and to some degree they choose based on nostalgia, so it is a conservative thing with all kinds of vocabulary a language learner is unlikely to meet.

The schooling system might also expose people to older literature in their own language and sufficiently specialist vocabulary might draw from the older vocabulary or grammar that is becoming less popular. This might conceivably help in understanding and retaining rare vocabulary. This is only speculation.

Second, and this is again speculation on my part, many languages have patterns for creating new vocabulary and expressions. A native user of the language is likely to understand things intuitively based on these patterns, if they can not name the patterns. This would help in decoding and memorizing strange words.