What obstacles prevent the most productive technologies from spreading to less developed
economies from the world’s technological frontier? In this paper, we seek to shed light on this
question by quantifying the geographic and human barriers to the transmission of technologies.
We argue that the intergenerational transmission of human traits, particularly culturally trans-
mitted traits, has led to divergence between populations over the course of history. In turn, this
divergence has introduced barriers to the diffusion of technologies across societies. We provide
measures of historical and genealogical distances between populations, and document how such
distances, relative to the world’s technological frontier, act as barriers to the diffusion of devel-
opment and of specific innovations. We provide an interpretation of these results in the context
of an emerging literature seeking to understand variation in economic development as the result
of factors rooted deep in history