The spirit level

5 stars for content, but 4 for presentation. The results are thorough, but the writing is dry—more engaging than a research paper, but I wouldn't consider it enjoyable past a mental exercise. Also, graphs are often labelled extremely vaguely (“high” vs “low”, “more” vs “less”, etc). I understand this was done in the name of simplicity, to show the correlation between graphs and between concepts, but really? I think most of us can read and interpret a numbered graph. As it stands, the reader has no idea whether a graph represents 5% of the scale of something or 100%.

Nonetheless, the research is intriguing, and The Spirit Level is a solid factual resource to back up assumptions that most of us have always shared: we are most happy and healthy when we live as equals with our peers.