The Pride Cycle - Explanation (Helaman Chapter 10-12)
There are several places in the Book of Mormon where a recurring cycle shows up that underscores the rise and fall of the Nephites and Lamanites (as well as individuals). This is particularly evident in Helaman chapters 3 through 12 and in 3 Nephi chapters 5 through 9. Mormon describes this behavior cycle in Helaman chapter 12 verses 2-6. This recurring behavior cycle is known today as Pride Cycle - see below: 
The Pride cycle is easy to identify by the four stages represented in the diagram. Each phase can last a week, a month a year - the time period is not fixed. What is important is the pattern. An individual (and in the Book of Mormon, a nation of people) receives blessings and experiences prosperity when they are humble, stay on the covenant path, obey God's commandments and show gratitude and humility for what they have. As they prosper, they begin to get prideful and forget how they became prosperous. They begin to believe that they deserve their wealth and blessing, forget about thanking God for his blessings, take for granted how they became prosperous and begin to look down on people who are in need and/or do not experience blessing. They blame these people instead of nurturing and helping them and become prideful and arrogant. This leads to the beginning of wickedness and forget God and wanted for riches and worldly possession. It leads to greediness, lack of compassion, and unholiness.
As the cycle progresses, these people begin to suffer the consequences of their action. Addictions, more greediness, wicked behavior, nastiness, disobedience, and just plan wicked behavior. As a result, the spirit withdraws and their blessings become less abound and they begin to suffer (and in the case of the nations, they are overtaken and destroyed).
When they finally are at their lowest, they turn to God and begin to humble themselves. The repent of what they have done, they become grateful for any blessings (no matter how small) and show gratitude, humility and compassion because they realize that only through God's compassion can they begin to heal.
As they come back to God, He begins to bless them. They receive blessings, begin to prosper again and recognize that this only occurs through their obedience and gratitude to God. And once they are in a good place again, it is easy to fall into the start of the cycle again.