Monbiot has a good post, pointing out what is, if you think about it, a basically obvious link between food and crime.
Nevertheless, it still scares me sometimes that what we think, how we act - in essence, who we are - is dependent to a certain degree on the balance of chemicals sloshing about in our bodies, and that this balance can be changed simply by altering what we eat.
That's not something that I like to think about, especially when it concerns what happens in my head.