Dontclick.it, an interesting interface design experiment by Alex Frank, included this amusing idea, the Mousewrap, to ‘train’ users not to click any more “through physical pain”.

It did make me think: is the use of anti-sit spikes on window sills, ledges, and so on, or anti-climb spikes on walls, intended primarily as a Skinnerian operant conditioning method (punishment – i.e. getting spiked – leading to decrease in the behaviour), or as a perceived affordance method (we see that it looks uncomfortable to sit down, so we don’t do it)? How do deterrents like this actually work?

It might seem a subtle difference, and in practice it probably doesn’t matter; it’s probably a bit of both, in fact. Most people will be discouraged by seeing the spikes, and for the few who aren’t, they’ll learn after getting spiked.

But on what level do anti-pigeon spikes work? Do pigeons perceive the lack of ‘comfort’ affordance? Or do they try and perch and only then ‘learn’? How similar does the spike (or whatever) have to be to others the animal has seen? Do animals (and humans) only learn to perceive affordances (or the lack of them) after having been through the operant conditioning process previously – and then generalising from that experience to all spikes?

What’s the accepted psychological wisdom on this?

Some spikes in Windsor, Poundbury, Chiswick and Dalston, UK.

Thanks to Steve Portigal and Page Sands for bringing this to my attention: the Brake-Fast Doggie Bowl is designed to stop dogs wolfing down their food quite as quickly as they would otherwise, which can cause painful (and dangerous) bloating. The raised prongs act like ‘traffic calming’ to slow down the dog’s eating.

This is a clever forcing function architecture of control, with the intention of making life better for the animal without risk of injury. There’s also another interesting feature – or rather deliberate lack of one:

(Q) The brake-fast(R) bowl slides all over the floor when my dog eats.
Why didn’t you put a non-slip edge on the bottom?
(A) We had a lot of discussion about the bowl sliding. In the end, we decided the purpose is to make the dog slow down their consumption rate, having the bowl slide adds that much more time when eating.

(From the Brake-fast website)

There are many examples of feeding systems or toys designed to entertain and distract dogs (and other animals) while being fed, since dogs clearly enjoy challenges, particularly when they result in a ‘reward’ of food. Steve points me to Kong dog toys which are designed to be filled with food which the dog can only get at by playing with the toy and chewing it, and I should also mention Simon Crilley’s Canine Joystick, a more advanced system which actually monitors the extent of the dog’s play before sending a signal to a wall-mounted food dispenser (another image here – PDF link).