Bettina Arndt's study stumbles at the first statistical hurdle if her sex diaries are drawn only from couples who are happy for the world to have a window on their bedroom. Her predictable conclusion is that fidelity and honesty are out, and affairs and self-interest are in. It is surprising that the Herald gives such potential bias free rein - unless of course smh.com.au is about to launch a Sex Diaries blog. Then it all makes sense.
Jon Guyer, Croydon
Writing to the papers is a great thing to do; even the unpublished ones sharpen your own thinking.