1.	Joseph Tainter, an anthropologist at Utah State University, and author of The Collapse of Complex Societies, offers a bleak outlook on the future of Western civilisation. He sees the worst-case scenario as a complete collapse - rupture in fossil fuel availability, causing food and water supplies to fail and millions to die within a few weeks. That sounds disastrous. But not everyone agrees. There are armies of scientists and engineers working on solutions, and in theory we can avoid past societies’ mistakes. Plus, many believe globalisation makes us robust.

2.	What exactly, however, do we mean by collapse? A group of researchers at the University of Maryland defines historical societies according to strict geographical limits, so that if some people survived and migrated to find new natural resources they would constitute a new society. By this criterion, even very advanced societies have collapsed irreversibly, and the West could too. But it wouldn’t necessarily mean annihilation.

3.	For that reason, many researchers avoid the word collapse, and talk instead about a rapid loss of complexity. When the Roman Empire broke up, new societies emerged, but their hierarchies, cultures and economies were less sophisticated, and people lived shorter, unhealthier lives. That kind of across-the-board loss of complexity is unlikely today, says Peter Turchin, an evolutionary anthropologist at the University of Connecticut, but he doesn’t rule out milder versions of it -the break-up of the European Union, for example, or the US losing its empire in the form of NATO and close allies such as South Korea.

4.	On the other hand, some people, such as Yaneer Bar-Yam of the New England Complex Systems Institute in Massachusetts, see this kind of global change as a shift up in complexity, with highly centralised structures such as national governments giving way to less centralised, overarching networks of control. “The world is becoming an integrated whole,” says Bar-Yam.

5.	Some scientists, Bar-Yam included, are even predicting a future where the nation state gives way to fuzzy borders and global networks of interlocking organisations, with our cultural identity split between our immediate locality and global regulatory bodies.

6.	However things develop, almost nobody thinks the outlook for the West is good .. “You’ve got to be very optimistic to think that the West’s current difficulties are just a blip on the screen,” says historian Ian Morris of Stanford University in California, author of Why the West Rules – For Now. So, can we do anything to soften the blow?

7.	Turchin says that by manipulating the forces that fuel the cycles, by, for example, introducing more progressive taxes to address income equality and the exploding public debt, it might be possible to avert disaster . And Motesharrei thinks we should rein in population growth to levels his model indicates are sustainable. These exact levels vary over time, depending on how many resources are left and how sustainably – or otherwise – we use them. The problem with these kinds of solutions, however, is that humans haven’t proved themselves to be great at playing the long game. New psychology research may help to explain why that is the case.

8.	Cognitive scientists recognise two broad modes of thought – a fast, automatic, relatively inflexible mode, and a slower, more analytical, flexible one. Each has its uses, depending on the context, and their relative frequency in a population has long been assumed to be stable. David Rand, a psychologist at Yale University, though, argues that populations might actually cycle between the two over time.

9.	Say a society has a transportation problem. A small group of individuals thinks analytically and invents the car. The problem is solved, not only for them but for millions of others besides, and because a far larger number of people have been relieved of thinking analytically – at least in this one domain – there is a shift in the population towards automatic thinking.

10.	This happens every time a new technology is invented that renders the environment more hospitable. Once large numbers of people use the technology without foresight, problems start to stack up. Climate change resulting from the excess use of fossil fuels is just one example. Others include overuse of antibiotics  leading to microbial resistance and failing to save for retirement.

11.	Jonathan Cohen, a psychologist at Princeton University who developed the theory with Rand, says it could help solve a long-standing puzzle regarding societies heading for ruin: why did they keep up their self-destructive behaviour even though the more analytical people must have seen the danger ahead? “The train had left the station,” says Cohen, and the forward-thinking folk were not steering it.

12.	This is the first time anyone has attempted to link the evolution of societies with human psychology, and the researchers admit their model is simple, for now. And while Rand and his colleagues make no attempt to guide policy, they do think their model suggests a general direction we might look in for remedies. “Education has got to be part of the answer,” says Cohen, adding that there could be more emphasis on analytical thinking in the classroom.

13.	But Tainter says trying to instil more forethought might be a pipe dream. If behavioural economics has taught us anything, he says, it is that human beings are much more emotional than rational when it comes to decision-making. He thinks a more pressing issue to tackle is the dwindling rate of invention relative to investment in R & D, as the world’s problems become harder to solve. “I foresee a pattern in the future where technological innovation is not going to be able to bail us out as it has in the past,” he says.