Recently The Wall Street Journal ran a short article about the way that a religious group becomes a cult.

Here's a quote:

The first is behavior control, i.e., monitoring of where you go and what you do. The second is information control, such as discouraging members from reading criticism of the group. The third is thought control, placing sharp limits on doctrinal questioning. The fourth is emotional control—using humiliation or guilt. Yet at times these traits can also be detected within mainstream faiths. So I would add two more categories: financial control and extreme leadership.

However, the author settles on one universal cultic trait: that of secrecy,  being what the author calls “unknowable to outsiders.”

Surely Mormonism qualifies.

For more information, see The Mormon Mirage 3rd Edition:  A Former Member Looks at the Mormon Church Today (Zondervan, 2009). Also available as an audiobook and as an expanded-text E-book for Nook, Kindle and other reading devices.