Left-handedness and economic development

Abstract

This paper studies the interplay between left-handedness and economic development, thereby contributing to our understanding of the relationship between evolutionary forces, human diversity and growth. We propose a novel theoretical framework in which economic development influences the prevalence of left-handedness through structural change and a genetic mechanism driven by differential fertility. In particular, the emergence of the industrial sector puts left-handers at a reproductive disadvantage, because of their lower manual ability and wages. This fertility differential changes sign as soon as the income-fertility relationship is reversed, and eventually fades away when the rise of human capital makes manual skills irrelevant. Our model thus explains the decline and subsequent recovery of left-handedness observed over the last few centuries in the Western world. We further explore the possibility that left-handedness in turn influences growth: despite their lower productivity in manual tasks, left-handers may enhance technological progress through cognitive skills that are conducive to innovation, and through their contribution to the diversity of the workforce. This implies that the link between handedness and economic performance varies across stages of development. We present empirical evidence that lends credence to the core differential-fertility mechanism of our model and suggests that left-handedness can positively contribute to growth, once the economy has reached a sufficiently high level of human capital.