The Greek that is typically translated in English as “shudder” is translated in Kandawo as inik tonj: “fear for their lives.”
Karen Weaver (in The PNG Experience) explains:
“Sometimes words and phrases needed for the New Testament come through quite unexpected sources. This happened when Mack and the Kandawo team had translated the book of James. They had used the Kandawo word for ‘fear’ in James 2:19 to describe the response of the demons to the one true God. As they discussed the meaning, this seemed to be the best translation of that verse.
“However, about this same time, Mack’s neighbor, Nathan, came to visit and shared a concern: His house was being overrun by mice! He asked if he could borrow a mouse trap and was grateful when Mack loaned him one.
“The next morning, Mack asked, ‘Did you catch any mice?’ Nathan replied, ‘Yes, eleven of them!’ Mack exclaimed, ‘Eleven! Wow! You surely caught them all.’ But Nathan was sure there were more.
“It turned out that Nathan was right because the next morning he reported to Mack that he had caught seven more mice during the night. The next night he caught five, and finally after the fourth night he reported that he had caught no more.
“Mack was happy for his friend, ‘You got them all!’ But again Nathan disagreed, ‘No, inik tonj.’ This was the first time Mack had heard that phrase, so he asked about it. Nathan explained, ‘There are certainly more mice, but they’ve all seen their comrades march to their death on that trap so now they inik tonj.’
“A smile crossed Mack’s face because he knew that if the translation committee approved of this phrase it would speak loudly in their language. The next day when the Kandawo co-translators came, Mack asked them about using this phrase in James 2:19. The two translators loved the idea! They edited the verse and it now reads, ‘The demons believe there is one God, and they inik tonj — They fear for their lives!'”