Why do balloons wrinkle as they deflate, and why do the wrinkles go away when you touch them?

Question

A question from the xkcd forums, and all the smart people there plus Yahoo! had no idea what the answer was. Help?

Answer 1

It is normal that when a balloon is blown up, its skin is taken far beyond the elastic limit of the material. Think of the size and shape of a balloon that was never blown up. When the balloon is deflated, the overstretched material relaxes partway, but it is still very thin and normally reacts to static electricity very easily and there is commonly static electricity generated from the air flowing out of the balloon and often while it is inflated (hairs stick to it for example). When you touch the wrinkles, the static electricity that was clinching the wrinkle flows away (into your finger) and the material relaxes.
Play with the thin plastic from dry cleaner bags with cotton gloves on then throw it down and touch it with bare skin and you will see similar things happening.

Answer 2

Touch Balloons