Schwarzenegger’s father, Gustav Schwarzenegger, served in the Nazi party during World War II and was wounded in the Battle of Stalingrad.
The Terminator star had one older sibling, Meinhard, who died at the age of 24 in a drunk driving accident after hitting a telephone pole.
Speaking about his Austrian father, Schwarzenegger said: “He was buried underneath buildings, rubble, for three days, and on top of that, they lost the war. They went home so depressed. Austria was a country of broken men. I think there were times where my father really struggled.”
The actor went on to recall how his father would make him and his brother “earn breakfast” and made them “compete against each other”.
“There was a kind of schizophrenic behaviour that my brother and I witnessed at home,” Schwarzenegger said. “There was the kind father, and other times when my father would come home drunk at three in the morning and he would be screaming.”
“We would wake up and, all of a sudden our hearts were pounding because we knew that meant that he could, at any given time, strike my mother or go crazy. So there was the kind of strange violence.”
Schwarzenegger said he believes his brother “started drinking because our upbringing was very tough”.
“The brutality that was at home, the beatings that we got from our parents sometimes – all of this I think he could not sustain,” he continued. “He was much more delicate of a person by nature.”
Access unlimited streaming of movies and TV shows with Amazon Prime Video Sign up now for a 30-day free trial
Schwarzenegger left Austria for America in 1968, aged 21. Three years later, after winning consecutive Mr Universe competitions, he was informed that his brother had died.
“The kind of upbringing that we had was beneficial for someone like me, who was inside very strong and very determined, but my brother was more fragile,” he said. “Nietzsche was right: that what does not kill you will make you stronger.”
Schwarzenegger spoke candidly about his Nazi father last year in an address to Russian citizens and military discouraging the invasion of Ukraine.
“To the Russian soldiers listening to this broadcast, you already know much of the truth that I’m speaking. You’ve seen it in your own eyes. I don’t want you to be broken like my father,” he said.
Elsewhere in the new, three-part Netflix docuseries, Schwarzenegger apologised for groping women in the past.
Arnold is out on 7 June on Netflix.