Galen's post about his pleasureful first tandem group ride recalls some persuings I've been having on tandems vs single bikes. Warning -- sweeping generalizations to follow.
I have noticed that tandem riders tend to have more consiousness about bicycles and riding than the average single bike rider, particularly on group rides. Perhaps it is because tandem cycling is already a "team effort." But in a group of single riders out for a club ride, you will often see more than one person weaving, riding too far left, being much less aware of automobile traffic approaching from behind, less likely to point out potholes, and other common riding courtesies. But in addition, when we ride our tandem around other single bikes, they tend to discuss other topics, but not the ride itself. In other words, it becomes a physical activity/social event where politics and movies are discussed. But the things experienced on the ride--an unsual barn, a newborn calf--typically go unremarked.
I am speculating, but I believe that the different behaviors are rooted in the basic assumptions about riding. Because tandeming requires more planning (ready, set, go!) and more on-going dicussion about riding (shifiting, braking), tandemistas generally think more about the actual experience of riding a bike. And because it already such a shared experience, the discussions are often about biking or what is enjoyed during the ride itself as opposed to external matters.
My prejudices are showing -- clearly I prefer it when people display more consciousness about the activity that they are engaging in. Which is one more reason why I enjoy tandeming.