I did my own research, involuntarily, and those who have smoked or are actively smoking will find the taste of regular food bland and subconsciously increase their intake of salt.
Another piece of research has discovered that most recipes spread by word of mouth as it were, will claim for the reader to add spices by taste.
This leads me to believe that in general, people are unreliable when it comes to measurements because rather than individual preference, it's more a matter of bodily trauma affecting perception.