As of November of 2008, the world population was estimated to be at 6.7 billion homo sapians. Malthus was wrong about our exponential increase in population resulting in starvation by the mid 19th century. Because even though we were increasing at a faster rate than food could be produced, he did not take into account for the technological advancements. So we are safe in terms of food, and it looks like space wouldn't be a problem, at least for a little while longer.
What about souls? Maybe this is complete nonsense to most people nowadays, but think about it. What if the human soul does exist, and there are a limited number which can be placed into mortal bodies?
Thousands of generations ago, there were less people on earth, so giving each newborn a soul was not a problem. But as populations exponentially increased, there would be an exponential demand for souls to be placed into bodies. What if there aren't enough souls for every individual? The only solution would be to fraction off the souls for each mortal body.
The result is that every successive generation, newborns receive less and less percentages of a complete soul.
Can this be the explanation for the increasing number of sociopaths out there? Or the fact that there is a demand for more sex and violence on television with every passing year(not that I am complaining, I love you HBO).
Think about it.