So the upshot of the study is that space is as much of a resource as food. Once the population hit the maximum density it stops growing. If the rats wanted to

So the upshot of the study is that space is as much of a resource as food. Once the population hit the maximum density it stops growing. If the rats wanted to increase their population they needed to build more housing, and build it vertically since they were literally boxed in. Is this relevant to humans? Probably, but not to the apocalyptic degree that people seem to be reading it as.