I pointed out an intertextual connection between 1 Nephi 11 and 15 some days ago. Reading chapter 18, I found two more. It seems that Nephi uses these to create a contrast, to show the readers "The Two Ways" and the consequence of choosing each of them. The example I linked does exactly that. The two examples I will give below do the same. In 1 Nephi 18:9-10
1 Nephi 16:20 and 18:169 And after we had been forth before the wind for the space of many days, behold, my brethren and the sons of Ishmael and also their wives began to make themselves merry, insomuch that they began to dance, and to sing, and to speak with much , yea, even that they did forget by what power they had been brought thither; yea, they were lifted up unto exceeding rudeness.10 And I, Nephi, began to fear exceedingly lest the Lord should be angry with us, and smite us because of our iniquity, that we should be swallowed up in the depths of the sea; wherefore, I, Nephi, began to speak to them with much soberness
And it came to pass that Laman and Lemuel and the sons of Ishmael did begin to murmur exceedingly, because of their sufferings and afflictions in the wilderness; and also my father began to murmur against the Lord his God; yea, and they were all exceedingly sorrowful, even that they did against the Lord.
Nevertheless, I did look unto my God, and I did him all the day long; and I did not murmur against the Lord because of mine afflictions.