Most descriptions of 4s describe us as having been emotionally damaged in some serious way as children. But I wasn't. No, really. I had a ridiculously placid childhood, with attentive parents, a nice neighborhood, a supportive extended family, and plenty of friends. I know--don't throw up yet.
So, I started reading Madame Bovary yesterday, perhaps the most 4ish book ever written, and I came across this passage that put it all in perspective:
Accustomed to peaceful sights, she was drawn to scenes of contrast and unrest. She liked the sea only because of its forms, and verdure only when it was scattered among ruins. She had to be able to extract some sort of personal benefit from things, and she rejected as useless anything which did not contribute to the immediate gratification of her heart, for her temperament was more sentimental than artistic and she sought emotion, not landscapes.
There are several paragraphs that follow this one, from Part I, Chapter 6, which continue to adeptly (I think) described the nature of a 4. (Though not in a particularly flattering way, I should add).