Sex is not socially constructed through human discourse. Almost all the plant and animals that you see reproduce sexually. Humans have reproduced sexually from the time of the very first humans. Fossils indicate that life forms have reproduced sexually for at least 1.2 billion years.[*]
Sex is a key variable in Darwinian evolution. Biological and behavioral factors important for reproductive success differ by sex. The social environment differs by sex for most primates. Human social roles and everyday tasks have differed by sex throughout recorded human history.
Sex differences in human communication should be expected. Human communication is a central aspect of human life. The same force that creates life creates sex differences.
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[*] On the earliest fossil evidence of sexual reproducing organisms, see Butterfield, Nicholas J., “Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of sex, multicellularity, and the Mesoproterozoic/Neoproterozoic radiation of eukaryotes,” Paleobiology, Vol. 26, No. 3. (1 September 2000), pp. 386-404. For comparison, archaic homo sapiens are thought to have evolved between 400,000 and 250,000 years ago. Thus sex has orders of magnitude greater evolutionary depth than does other common human characterizations such as black, tall, short, brown-eyed, blond, brunette, etc.