Wonder why your clients don't listen to you?  Perhaps this article explaining why men ignore nagging wives may give you some insight.  In short, many people will act in ways that are not in their own best interest, just because they wish to avoid doing what others want them to do.  This is called "reactance," and is defined as, "a person's tendency to resistsocial influences that they perceive as threats to their autonomy."  The article describes two interesting experiments that demonstrate just how ingrained this behavior can be:

In the first experiment, participants were asked to name asignificant person in their lives whom they perceived to be controllingand who wanted them to work hard, and another significant andcontrolling person who wanted them to have fun. Participants thenperformed a computer-based activity during which the name of one or theother of these people was repeatedly, but subliminally, flashed on thescreen. The name appeared too quickly for the participants toconsciously realize they had seen it, but just long enough for thesignificant other to be activated in their nonconscious minds. Theparticipants were then given a series of anagrams to solve, creatingwords from jumbled letters.

People who were exposed to the name of a person who wanted them towork hard performed significantly worse on the anagram task than didparticipants who were exposed to the name of a person who wanted themto have fun.

"Our participants were not even aware that they had been exposed tosomeone else's name, yet that nonconscious exposure was enough to causethem to act in defiance of what their significant other would want themto do," Fitzsimons said.

A second experiment used a similar approach and added an assessmentof each participant's level of reactance. People who were more reactantresponded more strongly to the subliminal cues and showed greatervariation in their performance than people who were less reactant.

"The main finding of this research is that people with a tendencytoward reactance may nonconsciously and quite unintentionally act in acounterproductive manner simply because they are trying to resistsomeone else's encroachment on their freedom," Chartrand said.

Though the article pokes a bit of fun at the husband/wife dynamic, this kind of behavior has very serious implications for advice-giving professionals and our clients.  I'd encourage you to read the entire study (cost:  $30.00).