Donald Trump has been accused of believing in the “racehorse theory” of genetics, which claims some people are genetically superior to others.

In an interview for US TV channel PBS, the Republican presidential nominee’s biographer Michael D’Antonio claimed the candidate's father, Fred Trump, had taught him that the family’s success was genetic.

He said: “The family subscribes to a racehorse theory of human development.

“They believe that there are superior people and that if you put together the genes of a superior woman and a superior man, you get a superior offspring.”

The theory, known as eugenics, first emerged during the 19th century and was used as a pretext for the sterilisation of disabled people until the practice was discredited after the Second World War.

Adolf Hitler’s justification for the Holocaust - in which 11 million people were killed, 6 million of them Jewish - was based on a similar theory of racial hierarchy.

The PBS documentary featured clips of Mr Trump on the campaign trial claiming that he “believes in the gene thing” and saying he had a “very high aptitude”.

It also ran footage of previous interviews from the real estate magnate's time as a reality TV star in which he shared his thoughts on the subject, including a 2010 interview with CNN.

He said: “Well I think I was born with the drive for success because I have a certain gene.

“I'm a gene believer... Hey, when you connect two race horses, you usually end up with a fast horse.

“I had a good gene pool from the standpoint of that, so I was pretty much driven.”

Mr Trump has become notorious for his bravado on the campaign trail and claimed he could solve problems that have plagued policymakers for decades with ease because he is a “smart guy”.

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Anarchist collective INDECLINE has created five statues depicting Donald Trump in the nude and placed them in five U.S. cities on Thursday morning. The statues are in San Francisco, New York, Los Angeles, Cleveland and Seattle. (Photo by Justin Sullivan/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States SAN FRANCISCO, CA - AUGUST 18: A passerby takes a picture of a statue depicting republican presidential nominee Donald Trump in the nude on August 18, 2016 in San Francisco, United States. Anarchist collective INDECLINE has created five statues depicting Donald Trump in the nude and placed them in five U.S. cities on Thursday morning. The statues are in San Francisco, New York, Los Angeles, Cleveland and Seattle. (Photo by Justin Sullivan/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States SAN FRANCISCO, CA - AUGUST 18: People gather around a statue depicting republican presidential nominee Donald Trump in the nude on August 18, 2016 in San Francisco, United States. Anarchist collective INDECLINE has created five statues depicting Donald Trump in the nude and placed them in five U.S. cities on Thursday morning. The statues are in San Francisco, New York, Los Angeles, Cleveland and Seattle. (Photo by Justin Sullivan/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States SAN FRANCISCO, CA - AUGUST 18: People gather around a statue depicting republican presidential nominee Donald Trump in the nude on August 18, 2016 in San Francisco, United States. Anarchist collective INDECLINE has created five statues depicting Donald Trump in the nude and placed them in five U.S. cities on Thursday morning. The statues are in San Francisco, New York, Los Angeles, Cleveland and Seattle. (Photo by Justin Sullivan/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States SAN FRANCISCO, CA - AUGUST 18: A passerby hugs a statue depicting republican presidential nominee Donald Trump in the nude on August 18, 2016 in San Francisco, United States. Anarchist collective INDECLINE has created five statues depicting Donald Trump in the nude and placed them in five U.S. cities on Thursday morning. The statues are in San Francisco, New York, Los Angeles, Cleveland and Seattle.(Photo by Justin Sullivan/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States SAN FRANCISCO, CA - AUGUST 18: A passerby has a picture taken with a statue depicting republican presidential nominee Donald Trump in the nude on August 18, 2016 in San Francisco, United States. Anarchist collective INDECLINE has created five statues depicting Donald Trump in the nude and placed them in five U.S. cities on Thursday morning. The statues are in San Francisco, New York, Los Angeles, Cleveland and Seattle. (Photo by Justin Sullivan/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States SAN FRANCISCO, CA - AUGUST 18: A passerby has a picture taken with a statue depicting republican presidential nominee Donald Trump in the nude on August 18, 2016 in San Francisco, United States. Anarchist collective INDECLINE has created five statues depicting Donald Trump in the nude and placed them in five U.S. cities on Thursday morning. The statues are in San Francisco, New York, Los Angeles, Cleveland and Seattle. (Photo by Justin Sullivan/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States NEW YORK, NY - AUGUST 18: Park authorities haul away a statue of a naked GOP presidential candidate Donald Trump that appeared in Union Square Park this morning on August 18, 2016 in New York City. The illegally placed statue drew hundreds of curious onlookers, who took selfie picture with the statue, which was signed "Ginger." A published report attributed the work to the anarchist collective INDECLINE, which titled the project "The Emperor Has No B--s." (Photo by Spencer Platt/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States NEW YORK, NY - AUGUST 18: A molded foot is all that remains of a statue of naked GOP presidential candidate Donald Trump that appeared in Union Square Park this morning on August 18, 2016 in New York City. The illegally placed statue drew hundreds of curious onlookers, who took selfie picture with the statue, which was signed "Ginger." A published report attributed the work to the anarchist collective INDECLINE, which titled the project "The Emperor Has No B--s." (Photo by Spencer Platt/Getty Images) Getty Images Naked Donald Trump Statue Appears Across The States NEW YORK, NY - AUGUST 18: Park authorities haul away a statue of a naked GOP presidential candidate Donald Trump that appeared in Union Square Park this morning on August 18, 2016 in New York City. The illegally placed statue drew hundreds of curious onlookers, who took selfie picture with the statue, which was signed "Ginger." A published report attributed the work to the anarchist collective INDECLINE, which titled the project "The Emperor Has No B--s." (Photo by Spencer Platt/Getty Images) Getty Images

In a December 2015 speech, he railed against the “incompetence” of the country’s leaders.

He said: “People are fed up – they are fed up with incompetence, they are fed up with stupid leaders, they are fed up with stupid people.”