How do people perceive subjective scales? Let's take a picture of apples:



Are there experiments conducted that study the distribution of the following answers to the question "How many apples are on this picture?":


Very little
Little
Normal
Many
Lots of


Well, of course, this specific picture doesn't matter, but this type of questions is important for many applications, like in surveys, when people rate things on subjective scales, so that in particular situations we can compare neither across questions with the same scale nor across persons answered the same question.

For example, think of 360-degree surveys when a person rates himself and is rated by others, so to compare in the end the two ratings.
If I understand you correctly, you are trying to learn about good practice in designing studies involving subjective scales? Then getting actual answers to such surveys might not be very helpful. You might rather want to know the impact of your survey design and the answering-environment on the answers of the respondent.

These are broad questions. Neither do I have the expertise nor the space to give you comprehensive answers here. Some suggestions though. As far as study design is concerned, you may want to consult Survey Methodology. In particular, section 5.3.5 deals with the implications of the type of scales used as possible answers. In fact, any other Survey Methodology textbook should cover this topic.

A lot of experiments also study the impact of social environment on perceptions and the construction of subjective opinions. Among others, Solomon Asch is a pioneer of experimental investigations of subjective perception. His most famous experiment is related to the conformity effect. He shows that people tend to conform to the perception of the group they are put in, even when this goes against strong visual evidences, see http://www.youtube.com/watch?v=FnT2FcuZaYI. 

In another famous experiment, Asch studied the "recency" and the "primacy" effect. The subject of the experiment where enumerated a list of personality traits (generous, peaceful, wise, mean,...) and subsequently asked to described the person. Asch question was whether, in describing the fictitious individual, people would rely more heavily on the first enumerated traits (the "primacy" effect), or would rather focus on the last ones they where presented (the "recency" effect). Asch results tend to show a dominance of the "primacy" effect.

Again, it would be too long to present a list of the numerous experiments and theoretical attempt to grasp perceptions mechanisms here. The literature is broad but the topic is classical. If you read french, it is notably covered in chapter two of "Psychologie Sociale" by Jacques-Philippe Leyens and Vincent Yzerbyt, but it should be covered in any good (social) psychology textbook. Unless you have a more specific question, this might be the right way to start learning about it.