Have we evolved to deal with long-term threats like climate change?

It can hardly be denied that humans are imperfect planners. For one, we have a widespread tendency to prefer immediate outcomes rather than those for which we must patiently wait– a kind of impulsivity that often cuts off our route towards future goals. Furthermore, our bodies and brains adapted to threats that were speedy and readily apparent, like snakes, not those that take decades to kill – like smoking. Most of us will panic if a snake strikes but a well-placed fear of cigarettes is hard to establish, despite the best efforts of public health campaigners. The way we deal with one of our most pressing large-scale threats – human-induced climate change – demonstrates our short-sightedness. We continue to prioritise immediate gains from fossil fuels at the expense of future flourishing, and we struggle to come to terms with the encroaching risks posed by the changes we are making to the global climate: including a mounting global extinction event.

Nevertheless, the story of human psychological evolution is about more than our myopic impulsivity and panic. We have also been endowed by natural selection with profound capacities for foresight and planning, in ways that have made us quite capable of managing threats like climate-change, pollution, and overfishing – if we can learn how to harness those capacities.

A central aspect of human impulsivity is known as ‘temporal discounting’: as soon as some benefit moves out of eye-line and into the future, its value deteriorates. This is one of the reasons people often find it so difficult to diet, save money, and plan for retirement. Discounting future rewards is not a unique hallmark of our species’ short-sightedness: we share this tendency with many mammals, birds, and even fish. Our preference for immediacy makes it hard for us to benefit our ‘future selves’ – like when we weigh up whether to eat the extra cookie after lunch – and it also impedes our attempts to benefit future humans, including our unborn descendants. Often, the only way to ensure a beneficial future outcome is to incur some cost right now: perhaps we must skip the second cookie after all. In the same manner, we must find a way to refrain from our reliance on fossil fuels that will cause problems for our children and their children.

Humans and other animals evolved to discount the value of future rewards because the future is uncertain. In ancestral environments, every additional hour between you and some future prize reduced the likelihood that it (or you) would still be around. Someone else might pluck the fruit you had been waiting patiently to ripen, or some predator or parasite might get you in the meantime. Nonetheless, we can be remarkably patient when it comes to our abstract long-term goals. People are willing to work and wait years for a promotion, a prize – or a date, sometimes – if they expect it will eventually pay off. One of the reasons we can do this is because we imagine the moment we will be told about the promotion, as well as all the benefits that will flow from it, letting these imagined events act as their own mini-reinforcements en route to the real thing. We can also use these mental ‘time travels’ into our future to guide us away from impulsive behaviour that would eventually cost us. Recent research shows that getting people to take a few moments to imagine the future while they make choices between immediate and delayed rewards can reduce their ‘impulsive’ preferences and encourage patience. We must be careful to use our imaginations wisely, however, because research also hints at the possibility that envisaging a threatening future might encourage more impulsive decision-making, instead: perhaps because it underscores the uncertainty of future rewards.

It is often said that a threatening future is difficult for humans to address because much of our psychological evolution took place on the savannah where the threats we faced were fast-paced and immediately obvious: like predators, snakes, or aggressive people. The threat of attacks by predatory animals goes far further back than the time our ancestors spent in the African savannah, however: it is a near-universal challenge for living things. The mechanisms humans have evolved to manage predatory threats are therefore deeply entrenched, overlapping significantly with the fear systems of other mammals. We are especially effective when those threats fit the bill for a predatory animal (sinister prowling) as opposed to an abstract notion (temperatures rising by 1°c). Indeed, a wide range of animals demonstrate a capacity for impressively flexible responses to threat – including with anxiety-like states that make them hyper-vigilant when they are at their most vulnerable.

Humans have all these tricks, but we also have a powerful supplementary skill: generating anxiety even when there are no cues of threat nearby at all. It might be hard to see anxiety as a blessing – indeed, anxiety disorders are among the most prevalent and crippling of psychological ailments. Nonetheless, when staring down the jaws of nature it pays to be prepared. Somewhere in our evolutionary journey we acquired the ability to respond to potential threats before they materialised – letting us craft in advance the spear that would eventually pierce the heart of a predator we were yet to meet. Many of the perils that we are summoning through our collective impact on the planet will only be encountered far down the line. Nonetheless, we are capable of imagining the consequences of this impact in the present moment. In this way, we can start to take right steps – and build the right tools – before the floodwaters touch the skyscrapers of Mumbai and New York.

Tackling climate change requires a long-term perspective – and, despite our shortcomings, this is exactly what humans have the potential to achieve. It has been argued that our capacity for foresight evolved because of the enormous benefits it affords to behaviours that increase fitness. The pinnacle of these behaviours is collaborative planning: imagining the future not only enables us to offset our impulses in favour of a better tomorrow and to act now in the face of future threats, but it also lets us share a vision of how the world could turn out if we act properly. Sharing a vision helps – but sharing a plan is better. Luckily, humans have evolved an avid proclivity to do both: we are constantly modifying, compromising, and improving our strategies through collective input and action.

As the only species on the planet with our level of foresight, we must now put this capacity to the test: can we use our imaginations to extend inter-generational empathy – to care deeply enough about our prospective descendants that we reign in our present impulses? And can we let critical imagined future dangers guide our current actions? If we can, perhaps the worst threats we foresee can stay simple fictions from our mental trips into the future.



Pollution: https://en.wikipedia.org/wiki/Air_pollution
Ice: https://www.pexels.com/search/climate%20change/
Crocodile: ttps://www.flickr.com/photos/reinrache/3564090161


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