Heredity is a science fiction

Science fiction

Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...

 short story

Short story

A short story is a work of fiction that is usually written in prose, often in narrative format. This format tends to be more pointed than longer works of fiction, such as novellas and novels. Short story definitions based on length differ somewhat, even among professional writers, in part because...

 by the American

United States

The United States of America is a federal constitutional republic comprising fifty states and a federal district...

 writer Isaac Asimov

Isaac Asimov

Isaac Asimov was an American author and professor of biochemistry at Boston University, best known for his works of science fiction and for his popular science books. Asimov was one of the most prolific writers of all time, having written or edited more than 500 books and an estimated 90,000...

. Asimov wrote the story, his twenty-third, in August 1940 under the title "Twins". It was rejected by John W. Campbell

John W. Campbell

John Wood Campbell, Jr. was an influential figure in American science fiction. As editor of Astounding Science Fiction , from late 1937 until his death, he is generally credited with shaping the so-called Golden Age of Science Fiction.Isaac Asimov called Campbell "the most powerful force in...

, editor of Astounding Science Fiction, on 29 August, and accepted by Frederik Pohl

Frederik Pohl

Frederik George Pohl, Jr. is an American science fiction writer, editor and fan, with a career spanning over seventy years — from his first published work, "Elegy to a Dead Planet: Luna" , to his most recent novel, All the Lives He Led .He won the National Book Award in 1980 for his novel Jem...

 on 4 September. It appeared in the April 1941 issue of Astonishing Stories

Astonishing Stories

Astonishing Stories was an American pulp science fiction magazine, published by Popular Publications between 1940 and 1943. It was founded under Popular's "Fictioneers" imprint, which paid lower rates than Popular's other magazines. The magazine's first editor was Frederik Pohl, who also edited a...

under the title "Heredity" and was reprinted in the 1972 collection The Early Asimov

The Early Asimov

The Early Asimov or, Eleven Years of Trying is a 1972 collection of short stories by Isaac Asimov. Each story is accompanied by commentary by the author, who gives details about his life and his literary achievements in the period in which he wrote the story.-Contents:* "The Callistan Menace" *...

. Heredity was the second Asimov story to receive a cover illustration.

Plot summary

Two identical twin

Twin

A twin is one of two offspring produced in the same pregnancy. Twins can either be monozygotic , meaning that they develop from one zygote that splits and forms two embryos, or dizygotic because they develop from two separate eggs that are fertilized by two separate sperm.In contrast, a fetus...

s, Allen and George Carter, have been separated at birth as part of a twin study

Twin study

Twin studies help disentangle the relative importance of environmental and genetic influences on individual traits and behaviors. Twin research is considered a key tool in behavioral genetics and related fields...

 to settle the nature versus nurture

Nature versus nurture

The nature versus nurture debate concerns the relative importance of an individual's innate qualities versus personal experiences The nature versus nurture debate concerns the relative importance of an individual's innate qualities ("nature," i.e. nativism, or innatism) versus personal experiences...

 question. Allen is raised on a highly developed Earth

Earth

Earth is the third planet from the Sun, and the densest and fifth-largest of the eight planets in the Solar System. It is also the largest of the Solar System's four terrestrial planets...

, while George has been raised in the provincial frontier society of Ganymede

Ganymede (moon)

Ganymede is a satellite of Jupiter and the largest moon in the Solar System. It is the seventh moon and third Galilean satellite outward from Jupiter. Completing an orbit in roughly seven days, Ganymede participates in a 1:2:4 orbital resonance with the moons Europa and Io, respectively...

. On their twenty-fifth birthday, they are introduced to each other and given the task of running the family farm on Mars

Mars

Mars is the fourth planet from the Sun in the Solar System. The planet is named after the Roman god of war, Mars. It is often described as the "Red Planet", as the iron oxide prevalent on its surface gives it a reddish appearance...

, where they have to work together in both day-to-day matters and unusual events. They find that they are forced to co-operate and also utilise 'primitive' technology in order to survive a major dust storm. After their initial mutual dislike, they develop a deep friendship.

After the story appeared, Scott Meredith, then a young science fiction fan named Scott Feldman, wrote to Asimov to point out a flaw in the story: two characters were introduced in the opening scene, then never heard from again. This led Asimov to pay closer attention to the more mechanical aspects of his writing.