Effects of culture and the urban environment on the development of the Ebbinghaus illusion

We investigated the development of visual context effects in the Ebbinghaus illusion across UK people and the Himba of Namibia who are remote from Western cultural influence. Traditional Himba showed no illusion up until 9-10 years, whereas UK children show a robust illusion from 7- to 8-years of age. Greater illusion in UK than traditional Himba children was stable from 9-10 years to adulthood. We also examined the Ebbinghaus illusion in Namibian children growing up in the nearest urban conurbation to the traditional Himba villages, finding a sustained influence of the urban environment across childhood and adulthood. We conclude that cross-cultural differences in perceptual biases to process visual context emerge in early childhood and are influenced by the urban environment