Population Density - a critical part of disease transmission.

And a lot of other issues.

It's been proven;

When Dr. John B. Calhoun kept dozens of cages of rats with moveable walls....so he could change the density while keeping them clean, and well fed....discovered that the more crowded together they were...the

-more aggressive
-more hostile
-more hoarding/greedy
-more likely to transmit infections/diseases
-more abnormal (male-male/female/female sexual behaviors)
-grouping/ganging-up

and;
-less normal sex
-less child concern/care
-less concern about raising chlidren

Many of the overcrowded populations crashed....wouldn't even recover when the numbers got small (due mostly to diseases)

Sound familiar?

And I read this in my junior year in HS...in 1962.

I've kept a copy on my desktop...I share it often.

Wake up people. Either we slow down our growth...or natural forces will.

[ncbi.nlm.nih.gov]

Here's follow-up research;

[eprints.lse.ac.uk]