Are human beings as rational as some people make out?
Matthew Sinclair on supermarket's promoting sweets:
If you think that labelling is important then you are assuming that people are good at making decisions about the kind of food they eat. That they care about their health and, if properly informed, know how to eat healthily. Or, you think that people should be free to decide for themselves how important healthy eating is to them. That's why you value giving them information, it allows them to make as much use of their remarkable ability to decide for themselves as possible.
By contrast, if you think that having sweets at the counter, or offering people discounts, will cause them to want things they shouldn't, and we should intervene to stop that happening, then you don't really respect their ability to decide for themselves at all. You think they're simpletons who can't possibly decide for themselves or are so pathetically vulnerable to pester power that they will be terrorised unless you hide the jelly babies in the corner. When Sainsburys take a pound off the price of my Coke they make me worse off.
But is it really that simple?
Human beings are not quite the rational agents economics often makes them out to be. As well as the ability to reason, we're also saddled with numerous evolutionary hang-ups that drive our behaviour, evolutionary hang-ups that may not have caught up with the modern world. As Daniel Dennet explains in "Breaking the Spell":
There is nothing "intrinsically sweet" (whatever that would mean) about sugar molecules, but they are intrinsically valuable to energy-needing organisms, so evolution has arranged for organisms to have a built-in and powerful preference for anything that tickles their special-purpose high-energy detectors. That is why we are born with an instinctual liking for sweets - and, in general, the sweeter the better.
We have an evolved strong desire for sugar because it benefited our ancestors to have it. However, they lived in a much less sugar-rich environment than we do. While the amount of available sugar has increased, our instincts have yet to catch up - leaving us with a strong desire for more sugar than is healthy for us. (Especially so in children).
The problem is that most of us probably don't know how much sugar is good for us (or how much sugar various items contain). We just know that our body desires that chocolate bar or that Eccles cake. Supermarkets, looking to boost their profits (as any good company should), will naturally aim to take advantage of this and seek to exploit any weakness in human nature.
This isn't a call for greater state intervention. (Personally, I think better education is the way to go). It is, however, a suggestion that the matter is more complex than the either/or option presented in the quote above.