Table of contents
Announcement

After ten years of exploring humanity in all its diversity, SAPIENS has concluded its publishing chapter.

While the magazine has closed, its living archive endures—open to all and preserving the many ideas, voices, and discoveries that deepen our understanding of what it means to be human.

When Sperm Compete, Nature’s Call Leads to Bigger … Testicles

Success in the living world is all about reproduction. Sperm competition has caused primate testicle size to increase.

The Half of the World That Doesn’t Make Out

Surprisingly few societies have romantic kissing in their repertoire.