Characteristic or Cause?

Often on stuttering list-serves I hear stutterers suggest that having a stutter pushes them to work harder to make up for their speech. Examples given include staying at work later than their colleagues who don't stutter, doing more than is required at the non-speaking aspects of the job, etc.

And I certainly fit into that category. I remember thinking that I had to do all the written work beyond what was expected to compensate for my stutter.

However, I just wonder whether this belief is putting the cart before the horse.

Could it not be that people with the drive to prove themselves, to be the cream of the crop, who have perfectionistic tendencies might be more likely to stutter? Could these tendencies be part of the cause rather than a result of stuttering?

After all, many stutterers observe that their stuttering lessens when they accept that they stutter and essentially allow themselves to speak imperfectly.

I just wonder.