Always cycling in highest gear, why? For all my life I have noticed that I always cycle in the highest gear (most of my bikes had at least 3x7, so it wasn't a lack of options) whilst most serious cyclists cycle on relatively low gears and are spinning like crazy from my perspective. Now, I get that taste definitely plays a role in these kind of things, but what I would love to know is whether serious cyclists learn to cycle in lower gear consciously or whether "it's just me" that loves cycling in a style where I move my legs as little as possible.

I realize this question is fairly broad and I hope the answer is fairly clear cut, but just to be fair it could theoretically be split up in:


Is there something bad about a cycling style in relatively higher gears?
What causes such a cycling style in the first place?


But I will keep it as a single question as those things are I believe extremely closely related.
Left to their own devices many will cycle at a cadence (a measure of how fast you spin) that approximates cadence of walking, an RPM of about 50-60.  So the fact you prefer a slower leg speed is not unusual. Trained cyclists will often have a cadence between 80-110 and up to 200 for sprints (track).


  Is there something bad about a cycling style in relatively higher
  gears?


Generally, many believe that pedaling at too high of a gear and too low of a cadence can cause more muscular and ligament stress.  Whether or not this bears out in terms of experimental evidence I am not sure (does anyone know of some experimental evidence?).  

A confounding factor on this is an individuals neuromuscular responses (i.e., how well they fire their muscles for the activity of pedaling in circles).  People that are not "good" at pedaling will often pedal more slowly and their inefficient pedaling patterns may also be responsible for higher muscular and ligament stress.


  What causes such a cycling style in the first place?


Generally, a faster cadence has been born from performance considerations. Cycling is not a natural activity.  It is an activity we invented that co-ops a lot of our mechanical and neurological pathways used for walking (e.g., corrective steering, steering into a fall, is very similar to walking when you step in the direction you are falling).  As such we need to train our neuromuscular responses to be more tailored to an activity like cycling.  Everyone who spins fast specifically trained to do so.  Most who train and cycle lots prefer to spin faster.  That said, there are some trained athletes who pedal relatively slower (although likely still faster than a non-cyclist). 

In terms of an "optimal" cadence there is still a lot of debate (e.g., Ansley and Cangley 2009) as it depends on what you are optimizing for (energetic costs, muscular stress, perception of effort, peak power).

Most will optimize based on perception of effort.  If you have not trained your neuromuscular pathways for the cycling motion it will be less developed and a slower cadence will likely feel more optimal.  As you ride more and your neuromuscular pathways become more efficient (i.e., you are better at recruiting muscles for the pedaling action) and a faster cadence will likely feel more "efficient."  

Of course this is a somewhat anecdotal assertion. I haven't personally run experiments tracking peoples progression from non-cyclists to cyclists. I have however accumulated years of observations from running cycling clubs. And as always there is lots of individual variation and the possibility of exceptions.  

In the end it is best to pay attention to your body and choose a pedaling speed that bio-mechanically work the best for you.