Reddit mentions of Developmental Psychology (Critical Thinking in Psychology Series Book 1395)

Age, up to a point is quite important. Piaget stages of development cover this quite strongly as there are points where children and adolsecnents are unable to 'critically think' as well as a fully development adult. Indeed you can look at correlations between moralistic development and critical thinking development and some argue that some people never reach the higher tiers of either of these.

As for after these phases I would agree re: life experience, I don' think people are talking down in this case but take a tried and true example of 'first love' - almost everyone goes through that experience of being with 'the one' and having their heart broken, and although you can explain it logically and the process that comes after it often is very hard to conceptualise it on a personal level without having experienced it.

If you more interested I suggest this book: http://www.amazon.com/Developmental-Psychology-Critical-Thinking-ebook/dp/B005CH00LU