14th century 

The first movie involved in our conspiracy happens to be one of the newest Disney-Pixar films, Brave, which is actually set in Scotland during the 14th Century.  The magic that is provided throughout the story can be traced to ‘the Will-o’-the-Wisps’ and has the ability to affect animals and objects.  For example, when Merida's mother eats the cake from the witch, she transforms into a bear, and when Merida enters the witch’s cottage, an unheld broom is seen sweeping itself.  This explains why creatures and inanimate objects are suddenly able to act in a way similar to that of a human.  The ‘the Will-o’-the-Wisps’ would enchant more animals and items over the course of many centuries, and the creatures would interbreed, blending in with the other animals.   They would keep their human mind set and knowledge, passing it on through generations.  But as the magic eventually wears off of the creatures, the enchanted animals regress back into the wild and their smarts continue to grow naturally instead.