Everything that is done in Ballroom Dancing has a reason. It is very important to know the "WHY" of what you are doing. The more that you know the "WHY", the more likely you are to do it properly and the better your dancing will become.
I know that all of you have seen ladies dance that look like they have had a stroke and their head is frozen to the left side of their body. Someone has told them that their head belongs on the left side of their body but didn't tell them "WHY". The lady's head to the left is generally true but it is more complex than that. The lady's head is part of the counter balance of her half of the two-headed four-legged animal. As the two-headed four-legged animal moves the dynamics of the lady's counter balancing head changes. Her head is constantly adjusting to the other half of the two-headed four-legged animal. Therefore, the lady's head is constantly moving and repositioning. This gives the lady a fluid look as she moves instead of that frozen stilted look.
Footwork is another example. Dancers are told: "Take that step with a heel". Without the "WHY", a simple forward heel step can make the dancer look like Frankenstein walking. Men are typically very susceptible to this problem because they tend to be quite literal. Footwork is almost always (there are always exceptions) a result of the body's position. The "ONE" step forward in Waltz from promenade position would result in an forward outside edge heel step. The outside edge heel step would be a natural response because of the shape of the body (as defined by the definition of promenade position). Without the "WHY" dancers try to step with their feet instead of letting their body shape take care of the footwork.
There are some things that are intellectually counter intuitive to the dancer unless they know the "WHY". For example, when executing "pivots" the tendency is to let centrifugal force take control of the rotation instead of letting the two-headed four-legged animal control it. If the partnership has a forward connection toward each other during the rotation, centrifugal power and rotational control can be achieved.
Ladies the "WHY" is imperative to you as the follower. It is very important for you to understand the "WHY" as it pertains to the lead and follow aspect of the two-headed four-legged animal. You must understand what specific part of the lead causes you to have a specific response. The leader dances very specific parts of the ladies body depending on what he is trying to lead. For example in the Rumba 'Fifth Position Break", he uses an invisible connection to move the ladies breaking right leg. The lady needs to know that the invisible connection exists and how it feels. The lady needs to know specifically what the lead feels like so she will respond unconsciously when it is lead. The more complicated the movement, the more specific the lead. Ladies, it is important that you follow by feeling instead of knowing patterns. If you dance patterns and you dance with someone who dances different patterns, you have a problem. If you dance by feeling, it doesn't make any difference what order he dances the elements you dance from element to element, what you feel.
The dancer can improve his or her dancing greatly simply by knowing the "WHY" behind all movements. Don't be afraid to ask the "WHY" question no mater who is giving you the information. Students are paying good money to instructors for their knowledge on dancing. Make sure that you get all the information you are paying for. Some instructors simply repeat words they have heard from other instructors or from video tapes without knowing the "WHY" behind the statement. If this is the case you might want to find a more competent instructor. It doesn't matter if the instructor is a high level competitor or an average instructor, demand your moneys worth and ask "WHY". One of the worst ballroom lessons I have ever taken was from previous U.S. Ballroom Dance Champions. Just because they are good dancers doesn't necessarily make them good instructors.
The more the partners knows the "WHY" about both sides of the partnership the better the movement of the partnership. The "WHY" of Ballroom Dancing can almost always be explained by examining the physics and geometry of the particular movement as it relates to the two-headed four-legged animal.