How the Languages We Speak Shape Our Realities

Aufgabe, grundnorm, gestalt, schadenfreude, kulturwort, übermensch, &c.

Many have their roots in the 18th century surge of German philosophy ignited by Kant which influenced the early psychologists like Freud and Jung (who were—if we're being honest—hardly more than philosophers, but proto-psychologists notwithstanding).

Insofar as I understand it, when such borrowing is done nowadays, it's not usually because the German word is perceived to have some different shade of meaning to a native one: rather because the borrower intends a different shade of meaning, perhaps deeming the risk of misunderstanding too great to use the native word. That is, the imported word as used in the context of the work is meant to have a precise and technical meaning as jargon. In using a different word, the reader is then forced to learn the new word with this new meaning, avoiding any connotations one might have with a familiar word—provided, of course, that this "new" word is unfamiliar ;)