First Hand, Second Guessed: on learning when not to trust our senses

Young children have trouble assimilating what they are told about the earth – that it is a sphere – with their experience of living on ground that looks and feels flat. They commonly reconcile these facts by imagining the earth as a ball capped by a flat platform, on which people can walk around without falling.

In this respect, they have intellectual ties to the early Roman Christian, Lactantius, who dismissed the idea of a spherical earth as a ‘folly’, because it implied that people in the antipodes would walk around with their feet above their heads. Not only that, he claimed, but crops would have to grow downwards, while the rain would fall upwards.

The idea of the flat earth and its misguided believers has featured in recent public debate. Barack Obama has said of climate change deniers that ‘we don’t have time for a meeting of the flat-earth society’. Bill Shorten once criticised Tony Abbott’s ‘flat-earth view’ on climate change, while former British PM Gordon Brown decried ‘behind-the-times, anti-science, flat-earth climate sceptics’.

It seems that the analogy works both ways. US Republican senator Ted Cruz said last year that ‘today, the global warming alarmists are the equivalent of the flat-earthers’, because ‘they brand you a heretic’. As the scientist Stephen Jay Gould has pointed out, people including the Ancient Greeks and some medieval Christians believed in a spherical Earth. The neat divide between historical flat-earthers and modern round-earthers is a convenient myth, but a potent one, used on one side of the debate to demonstrate the folly of rejecting science, and on the other to trumpet the heroism of calling out the mainstream.

When we are asked to think on unfamiliar scales, most of us very quickly butt up against the limits of our imaginations. We are not so different from the ancient flat-earthers, who gathered evidence on the limited scale at which they lived their lives, unable to imagine that their data gave an inadequate picture of the whole.

However, there are parallels between the two scenarios that go beyond the stinging analogies. We experience the world at comparatively narrow scales of space and time. Most of us don’t doubt that the Earth is a sphere, because we have flown around the globe or seen the NASA photographs of our planet from space. This information is, more or less, within the realm of personal experience.

But when we are asked to think on unfamiliar scales – for example, to comprehend the idea that gravity is the curvature of spacetime, that the universe is infinite, or that spinning electrons make objects appear solid – most of us very quickly butt up against the limits of our imaginations. In this way, we are not so different from the ancient flat-earthers, who gathered evidence on the limited scale at which they lived their lives, unable to imagine that their data gave an inadequate picture of the whole. In grappling with a question that was beyond the scale of their experiences, but seemed to be easily answerable, they fell into a cognitive trap.

Similarly, climate change is a large-scale phenomenon. To understand the problem, it’s necessary to look at global meteorological data, some of which describes the climate over thousands of years. Most of the associated changes are occurring incrementally, over long periods of time. But the phenomenon can appear to be deceptively small-scale, because it involves something familiar and accessible: the weather. Our bodies, equipped with temperature sensors, are our instruments; personal experience can feel like data.

Commentator Ryan Koronowski has compiled a list of tweets by Donald Trump, in which Trump notes occasions of snow and cold weather, and uses each to dispute the idea of global warming. Other writers observed that after parts of the US received record snowfalls in 2010, a large number of news reports expressed scepticism about climate change. In a recent survey conducted by the CSIRO, respondents who rejected mainstream climate science gave their primary reasons as ‘common sense’, ‘the weather’ and ‘historical events’.

Even amongst those who accept scientific projections, personal experience of the weather may make some resistant to climate change action. The idea that mean global temperatures might increase by 4°C does not seem to faze some denizens of the blogosphere, who dismiss such increases as negligible. When local temperature commonly fluctuates by more than this over the course of a day, or when predicted mean increases in sea level call up innocuous images of high and low tides on a beach, there doesn’t seem to be much call for panic.

It is not only deniers who are prone to faulty assumptions. In the CSIRO survey, the majority of respondents who accepted climate science gave ‘scientific research’ as their primary source of evidence, however many also gave the same non-scientific justifications as those who rejected the science. A US study found that subjects’ support for action on climate change increased after Hurricane Sandy, and was particularly elevated amongst people who had been personally affected by the hurricane. Other studies have found that people were more likely to say they accepted the science around global warming if they also believed that the temperature that day was higher than average, or even if they were asked the question in a warmer room. Current consensus is that no single extreme weather event or period of high temperatures can be causally linked to climate change, even though both are likely to increase in frequency.

The need to see something in order to believe it is arguably a fundamental human trait. Some philosophers of science believe that scientific thought is merely a natural extension of evolved thought processes.

When people use local weather to assess the accuracy of climate science, they are experiencing a phenomenon that psychologists call attribute substitution. The term describes any thought process in which an accessible attribute acts as a proxy for a relatively inaccessible one, usually without the subject realising that the substitution has taken place. In climate-change psychology, this kind of decision-making is weakly associated with lower levels of education.

The need to see something in order to believe it is arguably a fundamental human trait. Some philosophers of science believe that scientific thought is merely a natural extension of evolved thought processes. Steven Mithen describes the process of flaking a hand axe as basic hypothesis testing, because the outcome of each strike must be guessed beforehand. Critics of such views describe the scientific method as a radical break with evolved modes of thought, and point to the prominent role of cultural transmission. According to this view, understanding science involves accepting received wisdom, in much the same way that religious ideas, such as the ability of gods to defy natural laws, are often accepted without question.

Religion looms large in both flat-earth analogies and the broader climate change debate. Bizarrely, Cardinal George Pell has criticised climate science by likening it to an apocalyptic ‘new religion’, calling it ‘herdlike’ and ‘fundamentalist’, and claiming that it ‘demands sacrifices to appease capricious and cruel gods’. The methodologies of religion and science should not be conflated, but Pell may not be on entirely the wrong track. For non-experts, a scientific urge to question and demand personal proof can, counterproductively, result in the rejection of scientific ideas. Although it sounds like a version of the topsy-turvy world envisioned by Lactantius, perhaps science would be better served if some people approached scientific matters by abandoning their sceptical tendencies and, in meek and humble manner, accepting that some things are simply beyond their comprehension.