A recent study by a team of cognitive scientists in France, the UK and Switzerland found that the spatial environment one grows up in has a huge impact on navigation skills in adulthood.
Appearing in Nature this month, the study reports on a video game that 0.39 million people (0.2 million men and 0.1 women) from 38 countries were brought to play. The video game – Sea Hero Quest (SHQ) – had a built-in cognitive task, which involves testing people’s navigation skills. Previous studies have shown that Sea Hero Quest is an indicator of how well the player navigates urban settlements.
In addition, the authors calculated a metric known as the average road network entropy (SNE) of the largest cities in 38 countries; in the sense that the more organized and well-planned a city is, the lower its entropy and the more chaotic a city is, the higher its SNE. Since measuring city complexity is a convoluted concept, the average SNE of the 10 largest cities in each country was calculated (i.e. one SNE value per country). This made sense, since Sea Hero Quest players only reported their countries.
When the orientation performance measure was assessed, it was found that (a) younger participants performed better than those over 55, (b) men performed better than women, and ( c) better educated players performed better. This is largely in line with the findings of other similar studies. For example, a trial with rats found that older rats took longer than younger rats to find a destination and needed more tries before reaching a certain level of performance. The difference between men and women is also more pronounced in older age groups than in younger ones.
The study even found that participants who spent their youthful years outside of cities knew how to navigate better than city dwellers – so much so that it even compensated for the lack of education. “Having a higher level of education while growing up in a city is roughly equivalent to having a secondary level education while growing up outside cities in terms of orientation performance,” the study states. In fact, the effect is more pronounced among individuals from low NES countries. In other words, the simpler the country’s street pattern, the worse the spatial ability of people who grew up in cities compared to their non-urban counterparts. However, there are exceptions observed. For some countries – like India, Malaysia, Romania – being raised outside cities offered no significant advantage in terms of individual seaworthiness.
So why does growing up in a high SNE make for better navigational ability? The study explores a few reasons. First, growing up in an irregularly planned city means that one must frequently encounter varying street angles (ie angles that differ from 90o). Second, since our memory tends to optimize street names and turns, to minimize the amount of information we need to remember in an irregularly laid out city. Third, individual neighborhoods being more hierarchical in their planning, given their high density in an irregular city. All of these place increased demands on memory and orientation abilities, and are “likely to enhance the capacity of the neural systems that underlie [these skills]’.
Predictably enough, it was found that participants who grew up in well-planned cities performed better at regular, less entropic SHQ levels and those who grew up in more complex cities performed better at elaborate SHQ levels.
Additionally, the researchers designed another game, City Hero Quest (CHQ), specifically for the purposes of this study. CHQ is similar to SHQ, except the player has to drive a car around town instead of chasing a sea monster. Although all CHQ participants were from the United States, the impact of environment on orientation was similar to that of SHQ. Importantly, the effect of the current environment on CHQ or SHQ was not significant. This suggests that “the period of childhood is critical in predicting future spatial ability”, and also challenges the notion that spatial navigation is genetically determined.
The author is a researcher at the Indian Institute of Science (IISc) in Bengaluru and a freelance science communicator. He tweets at @critical