A 21st century cognitive portrait of the Himba, a remote people of Namibia

Adieu Bias: Debiasing Intuitions Among French Speakers

Recent debiasing studies have shown that a short, plain-English explanation of the correct solution strategy can improve reasoning performance. However, these studies have predominantly focused on English-speaking populations, who were tested with problem contents designed for an English-speaking test environment. Here we explore whether the key findings of previous debiasing studies can be extended to native French speakers living in continental Europe (France). We ran a training session with a battery of three reasoning tasks (i.e., base-rate neglect, conjunction fallacy, and bat-and-ball) on 147 native French speakers. We used a two-response paradigm in which participants first gave an initial intuitive response, under time pressure and cognitive load, and then gave a final response after deliberation. Results showed a clear training effect, as early as the initial (intuitive) stage. Immediately after training, most participants solved the problems correctly, without the need for a deliberation process. The findings confirm that the intuitive debiasing training effect extends to native French speakers.

The relationships between urbanicity, general cognitive ability, and susceptibility to the Ebbinghaus illusion

Previous studies have shown that, in samples of non-Western observers, susceptibility to the Ebbinghaus illusion is stronger in urban than rural dwellers. While such relationship between illusion strength and urbanicity has often been ascribed to external factors (such as the visual impact of the environment), the present study explored the possibility that it is instead mediated by general cognitive ability, an internal factor. We recruited a sample of remote Namibians who varied in their level of urbanicity, and measured their susceptibility to the Ebbinghaus illusion, their levels of education and literacy, and their general cognitive ability. The results showed that urbanicity was related to Ebbinghaus susceptibility, and that general cognitive ability, literacy and education did not mediate this effect, which is reassuring with regard to the findings of previous studies that did not control for these variables. However, we found robust relationships between urbanicity, on the one hand, and cognitive ability, education and literacy, on the other, which advocates for careful consideration of the impact of the latter variables in studies about the cognitive effects of urban environments.

Debiasing thinking among non-WEIRD reasoners

Human reasoning has been shown to be biased in a variety of situations. While most studies have focused on samples of WEIRD participants (from Western Educated Industrialized Rich and Democratic societies), the sparse non-WEIRD data on the topic suggest an even stronger propensity for biased reasoning. This could be explained by a competence issue (people lack the ability to integrate logical knowledge into their reasoning) or a performance issue (people possess the logical knowledge but do not know it is relevant). We addressed this question using a debiasing paradigm with the base-rate task on a sample of non-industrialized people, the Himba of Namibia. After a short training, most participants were debiased, lending credence to the performance account. Debiasing was however to some extent boosted by schooling and living environment suggesting that competence also plays a role (in that more acquired knowledge allows for a higher training benefit). Results imply that debias interventions can be successfully employed to boost sound reasoning around the world.