Whenever I make the call for positive leadership in South Africa, to liberate the country’s incredible potential, what fascinates me is the criticism I receive for my naivety.

People point to the challenges South Africa faces, and it’s certainly true they exist: GDP growth is at 0.8%, youth unemployment at 54.7%; we have a bloated public sector wage bill and a hefty budget deficit to fill; and tragic inequality.

My plea for positivity is not in spite of these challenges, but because of them – and it is rooted in science.

The optimism paradox – the gap between private hope and public despair – is an intriguing idiosyncrasy explained by behavioural economics.

On the one hand is our belief, that in our personal lives, our future will be better than our past, known as the optimism bias.

According to 2018 research from the Nobel Prize-winning economist Angus Deaton, based on data collected on 1.7 million individuals across 166 countries from 2006 to 2016, individuals are unwaveringly hopeful – to the point of consistently but irrationally believing they will be better off five years from now.

This difference between expected future well-being and current well-being was largest for Africa, roughly twice as much as the world. The optimism bias can be explained by evolutionary biology.

With our earliest ancestors facing threats posed by violence, disease, child birth and so on, the average lifespan was 21-35 years. To make any kind of progress in life, we needed to imagine a reality that was different, and one we believed was possible.

Counter-intuitively, however, this private optimism is contrasted with a persistent and pervasive public pessimism, known as declinism – the belief that our world (or country) is on an irreversible downhill trajectory. Declinism, too, has its roots in evolutionary biology. Hunter-gatherers were faced with constant environmental threats and were coded to seek out negative cues, a fundamental conditioning for survival. The global market and opinion research organisation Ipsos MORI surveyed perceptions of 26,489 people across 28 countries as to how the world is changing. Sixty-five per cent of respondents believe the world is getting worse, fuelled by misperceptions of how the world has changed. The degree of optimism about the future differed hugely according to the level of people’s knowledge about global development – those that were most pessimistic about the future tended to have the least basic knowledge on how the world has changed for the better. We South Africans suffer from this declinist outlook acutely. Not only are South Africans gloomy about how the world has changed and what the future holds, on a broad range of issues, South African respondents gave the least accurate guesses of where the figures on global and national development stood – out of all 28 countries. We are not just impervious to the facts on progress; the study revealed we are confident in our erroneous perceptions.