I don't suggest telling the person that you're inspecting her "age rings"....I don't think it will go over very well. (you can see them come down from the collar bone and attach in the middle/upper sternum. The middle point connecting tells the age. I have a clear "20s" and my "30s" is just barely connecting - my best friend explained this to me when I turned 30. I was very surprised - it's funny because now I notice them on other people)