They master communication skills that frequently improve the atmosphere in the family. Parents discover how to be encouraging rather than discouraging. They begin to focus on what is important and how to avoid unnecessary power struggles. There are many unexpected benefits. Parents frequently report that the principles learned in class help them work more successfully with other adults.
Marriages sometimes improve, as do relationships at work.
Most parents soon realize that without education they tend to rear their children they way their parents reared them. There is nothing wrong with that, but times change. Children are more complicated today. Society presents relentless temptations. Parent education adds to the skills parents already have.