No studies or "official" references. Having been an active and avid rider, racer, commuter, I do have a bit of experience in this area. Most of the people I know who have saddle issues are casual riders, and never spend the time (ride the miles) to acclimate their points of contact with their saddle. They ride once or twice, their undercarriage gets sore, and they proclaim: "My saddle is uncomfortable".

Some people actually have wider or narrower than "normal" sit bones. A good bike fit person can make this determination, and then recommend an appropriate saddle.... of course they have to get kind of up close and personal with your nether regions to do the measuring.

If one doesn't want to take my word for it, perhaps Sheldon Brown's wisdom would be more acceptable.

http://www.sheldonbrown.com/saddles.html

Sheldon does state that a good tensioned leather saddle (Brooks) will "break-in" over time, but again, someone actually has to put in enough time in the saddle to make this happen. I have ridden many kinds of saddles over the past 20+ years, and the only time I have ever had a problem was doing too many miles on early season rides. Now that I ride year round, I can jump from saddle to saddle and not have any issues.