The hundredth monkey
There is a certain species of monkey that lives on two different islands. The two groups of monkeys that live on the two islands are just alike, the same species, the same basic environments, and hence, the same basic lifestyles, but the two islands are far apart, and the monkeys don't swim, so there is never any contact between the two groups. One day, on the first island, one of the monkeys somehow makes a discovery that by taking a piece of the fruit which is their main food down to the water and soaking it, it becomes much easier to peel. This is a wonderful discovery, a real breakthrough. Soon, the other monkeys on the island begin to catch on, and learn this helpful new technique. Now, although this species of monkeys may have lived for generation upon generation on these two islands without making this discovery, now that it has been done, by the time the hundredth monkey on the first island has learned it, there will be monkeys doing it on the second island as well.
[Snipped from http://www.hootenanny.com/hoot/3/sheldrake.html]
I have always had my own doubts about the hundredth monkey principle. Does a