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It’s a Boy! Evidence for Sex Ratio Adjustment in Humans

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Choosing Sexes

Part of the book series: Fascinating Life Sciences ((FLS))

Abstract

Since the beginning of human existence, there has been a keen interest in the factors that influence whether a boy or girl is produced and the development of practices or methods to control it. While the overall natal ratio of boys to girls produced by humans hovers at a stable 1.06 boys for every girl, there is now evidence that these sex ratios vary substantially among populations, in response to severe life events, in conjunction with the position and timing of intercourse, and even with ambient temperature. In this chapter, I compile the evidence implicating many of these factors as modulators of offspring sex ratios in humans and discuss how these influences may interact to determine whether a boy or a girl is produced.

Now by thy looks

I guess thy message. Is the queen deliver’d?

Say, ay: and of a boy.

From William Shakespeare’s Henry VIII

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  1. Department of Poultry Science, The University of Georgia, Athens, Georgia, USA

    Kristen J. Navara

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Navara, K.J. (2018). It’s a Boy! Evidence for Sex Ratio Adjustment in Humans. In: Choosing Sexes. Fascinating Life Sciences. Springer, Cham. https://doi.org/10.1007/978-3-319-71271-0_2

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