discovery - Do unique icon contours help people scan?

Many years ago, I ran across a good icon design tutorial. It said that having unique contours to icons help users scan for the item they're looking for. If this is true, why don't iPhone and Android app icons use unique contours?

iPhone icons are all rounded squares. The only visual cues for zeroing in on an app is the inner design. I don't know about you guys, but sometimes it takes me 5 seconds to find the Map app.

Android icons only have a few contour variants: square, circle, talk bubble, ... In my opinion, Android's limited set of contours is worse than iPhone's uniform contours. It tricks people into utilizing the contours to help them parse, even though it won't help them. For example, I'm often confused when trying to find the music speaker icon because it has the same concentric circles as the camera and settings icon.

What ever happened to good old fashioned Windows style icons? I think Window's icons elevate scanability over consistency / style. I never find myself aimlessly gawking at Windows icons because almost all contours are unique.

Answer

Many years ago

That's probably the key factor. The rendering technology we now have is considerably different than what we had in say 1985 or 1995.

Now, that shouldn't really change the principles of good icon design, but it has changed the trends over the years. OS X and Windows have become progressively 'shinier' over the years at times implementing almost full blown illustrations and 3D renderings as their icons. And people can be suckers for shiny…including those of us that design the icons. ;o)

Fortunately, it seems that we've gotten that mostly out of our system and we're now moving back towards a saner visual icon language. Windows Phone 7 is an interesting move back towards the traditional concepts of icon design.

Now, all that said, the question was more about app icons. An app icon is just as much about UX as it is about what the marketing department wants/needs. I can be a bit more forgiving of the app icon than the internal UI icons of the app. App icons are really mini advertisements. But I do agree, some of the icons (including Maps), become lost as it's less of a true icon and more of a small photo.