Anecdote: I found the iPod really unintuitive and un-natural to use.

I'm one of those people that can pick up just about any gadget and work out how it works (much as I expect you are dear reader). I'm the go-to for computer repairs and questions for family and friends, I help people work their mobile phones, set-up their AV equipment, etc., I've done stage lighting, sound engineering, a very little electronics .. you get the picture. I can even work a Mac!

My play on this whole question is that an interface is intuitive if I can work it out without the instruction booklet in a short time. Pretty handy-wavy for sure.

(not attempting to pick a fight, just feel I need to point out...)

I'd generally argue that the reason you have troubles with the iPod is because you've learned to think like an engineer... ie, unlearning how to think like an uninformed user in the process. You're not exactly their target audience (nor am I).

Out of pure curiosity, which iPod style is this referring to? Scrollable-wheel, click-wheel, touch, shuffle? I personally find the click-wheel versions to be a bit annoying because they don't register scrolling accurately enough.

I once made a comment on HN about user interface and the advent of touch, in regards to the iPad being great for people who just don't want all that complexity, and a commenter replied to me saying that our parents would then have to learn a completely new user interface paradigm, the touch interface.

My response was that reaching out and touching something that you're interested in is about as intuitive as you can get. Even my kitten 'understands' that if she wants to interact with the sun falling from the sky in Plants vs. Zombies, she just paws at it. She does have a tendency to attack randomly and plant things everywhere, but she's got the basic idea.

A lot of other tech-minded people, however, seem intent on trying to shoehorn the touch interface into their concept of a WIMP UI, then complain when it doesn't work. One coworker, on the day the iPad was announced, even exclaimed 'But it doesn't even have a stylus!', to which seven other people in the department replied 'Good'.

How do you know you just aren't conversant with "the way most engineers would do this"? That would mean you are using your familiarity with a certain set of conventions and not necessarily using your intuition.

>How do you know you just aren't conversant with "the way most engineers would do this"?

I don't use the term "intuition" in the exact way I use the term "intuitive" wrt a UI. I warrant that you're correct that my thought processes could align to some extent with those of the creators of any interface that I'm attempting to grok and that this appears as if the interface is intuitive.

Intuitiveness (rather than "intuition" to make the distinction I hinted about above) in an interface that relies on metaphor (affordance of buttons enhanced by shadow, etc.) is simply about familiarity.

A previous comment mentioned a simple light-switch as being possibly lacking in affordance for a jungle-dweller who lacks knowledge of our technology. I'd agree that they're unlikely to intuit what to do, but the interface to my mind is intuitive in that once one tries it then the feedback leads to a ready analysis of the effect and enables rapid understanding of the superficial workings.

What you're saying is that a light switch has high discoverability.

Like all things supposedly "intuitive".

What's intuitive? It's all learned from something. We can't even pick our nose when we're first born, we have to figure out how to move our arm.

We are born with a fear of heights. It takes a little awhile to develop object permanence, but there's very little risk of people not getting it. The brain is not a blank slate -- that's ideological dogma from bygone days. Science is showing the brain has a lot of functionality baked into the hardware. Read Steven Pinker's books for the general interest overview.

There indeed is a real intuitive.

And how would you suggest leveraging it for computer interfaces? Putting the dangerous things over the edge of a cliff?

Read Pinker's books. There's a lot more than my two examples. (Though either one alone demolishes your earlier claim that all "intuitive" is learned.) There's a lot of intuitive stuff around Geometry alone that painters have been exploiting since cave paintings. I think there's plenty more we can do as computer people with that alone.