Have you ever heard of people called the British school of diffusionism? Well, they were a group of people who believed that cultural ideas and things (like tools, clothing, and even language) could spread from one group of people to another. Imagine a game of telephone where one person whispers something into another person's ear, and then that person whispers it to someone else, and so on. The idea might change a little bit each time it is whispered, but it still gets passed along.
The British school of diffusionism believed that this is how many cultural practices and ideas spread throughout the world. For example, they might argue that the idea of writing started in one place and then spread to other parts of the world as people learned about it and started using it themselves.
Now, this idea might seem obvious to us today, but it was actually a pretty big deal back when the British school of diffusionism was first formed. Before this, many people believed that cultural practices and ideas could only arise in one place and couldn't spread to other parts of the world. But the British school of diffusionism challenged this idea and opened up new ways of thinking about the way cultures interact with each other.
So, in short, the British school of diffusionism believed that cultural practices and ideas could spread from one group of people to another, much like the game of telephone.