After reading an old article, by Tom Wolfe, about two studies that dealt with animals and overcrowding I felt the need to share the information. The first was John Calhoun's study of Norway rats. The second was John J. Christian's research on Sika Deer. At a certain point the results for each population became disastrous as the animals exhibited pathologies and even experienced ‘unexplainable' death. Both made me begin to think about human populations and how much of an influence crowding has on us.

Calhoun's Study of Norway Rats

The first researcher, John Calhoun, placed 80 Norway rats in a cage with four sections and two walkways that would lead from the outside compartments to the inside compartments. According to Tom Wolfe, if there are more than 200 of them in one fourth of an acre they will begin to "die off."

So, what happens when you place 80 in relatively small cage?

Calhoun made sure that they had enough water, food and shelter necessary to survive but the rest would be up to the rats. Soon enough, the animals descended into what Calhoun described as a "behavioral sink." This term is used to explain the behavior of animals that gather or are forced to live in a space too small to accommodate them.

The rats at first developed a sense of order, but that soon went ‘haywire.' At the ends of the cage an alpha male took over and kicked the other males out. According to Wolfe, the alpha males would take eight to ten females as concubines. This meant that from 58 to 62 Norway rats would be forced to live in the middle two compartments.

Chaos resulted as no sense of order or balance could come from that many rats being trapped so close together. The male rats fought constantly and began to ignore rituals and force themselves on female rats. They also began to perform bisexual and acts. Some rats wouldn't even move in the daytime and would wait for the other rats to go to sleep before they would walk around. No rat was safe from molestation and any attempts to leave the confines of the middle compartments by male rats were checked by the alpha male at either end of the cage. They were trapped in chaos.

The alpha males, and their concubines, it must be noted, grew much larger than the other rats and maintained their health and vitality. The female concubines also had free reign and would venture in and out of the middle compartments as they pleased.

John J. Christian's Sika Deer Study

In the next study, John J. Christian studied Sika deer on James Island in the Chesapeake Bay. These deer required at least three acres per deer in order to thrive. Yet, during the six-year study, on the 280 acre island, the Sika population reached nearly 300.

Remember, an individual Sika deer needs at least three acres to prosper. So the increase in numbers for them turned out to be disastrous. When their population hit 300 all of a sudden the deer began to drop dead.

The newly deceased deer appeared to have no health maladies. However, autopsies revealed that they died from enlarged adrenal glands. The over-populated island proved to be too much for the herd and many died from being ‘over .' However, as the population adjusted to a numerical range that would support their three-acre per deer spatial needs, the deaths stopped occurring.



These two studies raised a number of concerns for me because even though we like to separate ourselves from other animals that inhabit the earth, we aren't immune from environmental influences. Further, we all tend to have ideas or know theories from research about what happens when humans are placed in crowded environments. But, how often do you ask yourself what happens to you or how do you react when you are in an overpopulated setting?

Psychological theories such as actor-observer and cite how humans have the tendency to blame the or disposition of the misbehaved when they act a certain way. The flipside of these two theories is that when we judge our own failings we often assign blame to situations and not to our personalities.

However, even with knowledge of these theories, when we behave out of character due to ‘overcrowding,' do we really look to our environment? And if we do assign fault to our environs, what do we do to address environmental concerns and our behavior?

Bakari Akil II, Ph.D., is the author of Super You! 101 Ways to Maximize your Potential! Check out his page on Twitter.