superfemale

zoology

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Last updated

July 14, 2026

Quick Summary

A "superfemale" is a term used in zoology to describe a female with three X chromosomes (XXX) and two sets of autosomes. This condition is a type of sex chromosome anomaly. In humans, this can lead to individuals who appear as normal females, though fertility may vary.12

The term "supermale" is sometimes associated with XYY-trisomy, a condition where a male has an extra Y chromosome. While early theories suggested a link between XYY-trisomy and increased aggression or criminal behavior, later studies have cast doubt on this direct correlation.3

Sex determination is a complex process controlled by chromosomes. In humans, females typically have two X chromosomes (XX), and males have one X and one Y chromosome (XY). Abnormalities in the number of sex chromosomes can lead to various developmental and reproductive outcomes.24

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Abnormal chromosome effects
…and are called, in fact, superfemales, although only some will be fertile. Those with the XO (one X, but lacking Y altogether) constitution, a much more common condition, are also feminine in body form and type of reproduction system but remain immature. Individuals with the XXY constitution are outwardly males…
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…and are called, in fact, superfemales, although only some will be fertile. Those with the XO (one X, but lacking Y altogether) constitution, a much more common condition, are also feminine in body form and type of reproduction system but remain immature. Individuals with the XXY constitution are outwardly males…
Read More