Life on Earth evolved in an environment of constraints: resource limitations, disease and predation all put lids on behavior and reproduction. Consequently, the mechanisms to deal with those constraints have no "brakes", because nature provided them. There's no reason to have tight control on over-eating, because such a situation rarely arose. There was no reason to protect reward circuitry in general from overstimulation. But now we're starting to remove those constraints. Solve food scarcity, and we get obesity. Go straight to the reward center (without a real external reward), and we get heroin and video game addiction.
This is the biggest problem we face in any post-scarcity world, or (more broadly) in any world where our behavioral regulation is freed from the constraints that sculpted it for billions of years, whether in reality (because there really is more than enough food) or virtually (because you can just shoot up and feel good). This problem has even been advanced to explain the Fermi paradox, since whatever behavior regulation intelligent aliens evolve, presumably when they solve their own constraints, they will run into the same problems - perhaps with species-destroying consequences. The more complete and effective a representational system is*, the faster and greater the instability it creates in the system.
You might think of a science fiction story where curious and powerful aliens have put humans in a kind of terrarium where the weather is always fair, there's always enough to eat, there's no physical danger, and where there is always another territory to move into, with no loss of security, if you burn too many bridges with the ones in this one. That is to say, someone looks at you the wrong way, or your significant other mildly irritates you - why stick around? The aliens have guaranteed there will be another handsome gentleman/pretty lady waiting for you when you get to the new territory. And when you get there you wonder idly if these are real humans also in the experiment, or were whipped up and memory-programmed by the tissue replicator twenty minutes before you got there; or maybe you were, before your new mate got here. But you're taken care of; does it matter? (California sometimes feels like it's almost there.) In a world of limitless security and resources and even others' company, why ever tolerate the least inconvenience?
A scenario similar to this that happens in the real world is the strange discomfort of working alongside someone who is wealthy independent of their jobs. Why are they even here, people might ask resentfully - and indeed, from anecdotal experience, when these people get annoyed, they quickly leave, because why not? They have security and more territory.
So what happens to people when all the constraints are removed, when they're both wealthy and not subject to censure by broader political forces? That is to say, how do humans behave when all the brakes are off?Predictably. From "The Prince Who Blew Through Billions" by Mark Seal, from Vanity Fair in July 2011:
On the brother of the Sultan of Brunei, Prince Jefri Bolkiah, who has "probably gone through more cash than any other human being on earth.": "The sultan's biggest extravagance turned out to be his love for his youngest brother, Jefri, his constant companion in hedonism. They raced their Ferraris through the streets of Bandar Seri Begawan, the capital, at midnight, sailed the oceans on their fleet of yachts (Jefri named one of his Tits, its tenders Nipple 1 and Nipple 2), and imported planeloads of polo ponies and Argentinean players to indulge their love for that game, which they sometimes played with Prince Charles. They snapped up real estate like Monopoly pieces—hundreds of far-flung properties, a collection of five-star hotels (the Dorchester, in London, the Hôtel Plaza Athénée, in Paris, the New York Palace, and Hotel Bel-Air and the Beverly Hills Hotel, in Los Angeles), and an array of international companies (including Asprey, the London jeweler to the Queen, for which Jefri paid about $385 million in 1995, despite the fact that that was twice Asprey's estimated market value or that Brunei's royal family constituted a healthy portion of its business).This reads like an account of what each of us would do if we found out tomorrow we were in a simulation, with power over said simulation. This is what happens when the brakes are off. If you object that this is an exception or an extreme example - I guarantee that this behavior happens more among the fabulously wealthy and powerful. Well of course, you again object, other people can't behave that way! But then if the tendency wasn't there, why should it happen at all? And (more to the point) do you seriously think you would be any better-behaved? Of course you would; you're biologically and/or morally superior to these folks and would never let that kind of thing happen. (Also note that lottery winners, with a sudden random infusion of karma or whatever you call the points in our game - that's right, "money" - are known for going off the rails, and being more miserable and more likely to go bankrupt than the general population. Also, see "athletes from poor backgrounds suddenly signed up to multi-million dollar contracts in pro sports".)
"Back home, the sultan erected a 1,788-room palace on 49 acres, 'which is without equal in the world for offensive and ugly display,' in the words of one British magnate, and celebrated his 50th birthday with a blowout featuring a concert by Michael Jackson, who was reportedly paid $17 million, in a stadium built for the occasion. (When the sultan flew in Whitney Houston for a performance, he is rumored to have given her a blank check and instructed her to fill it in for what she thought she was worth: more than $7 million, it turned out.) The brothers routinely traveled with 100-member entourages and emptied entire inventories of stores such as Armani and Versace, buying 100 suits of the same color at a time. When they partied, they indulged in just about everything forbidden in a Muslim country. Afforded four wives by Islamic law, they left their multiple spouses and scores of children in their palaces while they allegedly sent emissaries to comb the globe for the sexiest women they could find in order to create a harem the likes of which the world had never known."
An astute observer will say, "So what if people descend into depravity? If you're in a simulation or the aliens' zoo or you're royalty and don't hurt anyone, if you're happy with harems and Ferraris, fine!" That would be fine. But the problem is these people often seem not to be happy. Here it's hard to get data, but they are not invariably happier than other humans and in fact often have considerably troubled emotional lives. Again, they're using nervous systems built for an environment of resource and social constraints. It should not be surprising that they experience boredom, restlessness, and emptiness. In fact in the developed world it's not just the ultra-wealthy that experience these things. That said, it's sure better than starving or being eaten by tigers, but it seems those are our two alternatives: obese or at best bored, versus running from predators, starvation, and stronger neighbors. Yes, I fully recognize the pessimism of this position.
So, there's an addition to Malthus here. Malthus merely pointed out that when all constraints are relaxed but one, that constraint will limit (and his rule concerned, specifically, energy input as the unrelaxed constraint, but you can imagine for example a dense population of well-fed non-preyed-upon humans being periodically cut down by plagues). The addition is that when all constraints are relaxed, the system becomes unstable, whether that system is a cell (cancer) or an individual. The more powerful the system - which can be approximated by how fast it can change - the faster it will become unstable.
*The first representational system to evolve on Earth was the gene: the proteins it codes for are indirect mirrors of a DNA strand's environment - and as the environment changes, the genes change. As life became more complex, systems appeared that became able to more and more rapidly and/or accurately reflect parts of the environment beyond the replicator: the cytochrome P450 system which is a remarkably non-specific but effective metabolism system (which is how most drugs are broken down even though life on Earth has never seen these molecules before) and the immune system, which produces high-affinity molecules with a process of directed by limited somatic mutation. The ultimate such system however is the development of large numbers of cells signalling with ion channels, which can represent much more information much faster, and in humans has expanded to allow the assignment of arbitrary symbols to novel relationships (language). While we still can't assume that our language-enhanced nervous systems can represent every possible state external to themselves (any more than the immune system can do so), it's still by far the fastest-acting system and the one most likely to spell its own demise. As an aside, it's probably no surprise that plants that have begun to evolve "behavior" of a sort - the carnivorous plants - also use ion channels. Assuming causality is unidirectional, what happens first matters, and therefore so does speed.