Elon Musk 'Wants Smart People to Have Kids,' Executive He Welcomed Twins with Says in New Book

Elon Musk welcomed twins with Neuralink exec Shivon Zilis in November 2021

Elon Musk “wants smart people to have kids,” according to a new biography about the billionaire.

In Elon Musk by journalist Walter Isaacson, which comes out Tuesday, Neuralink executive Shivon Zilis, who welcomed twins with the 52-year-old billionaire in November 2021, said Musk "encouraged" her to have children.

“He really wants smart people to have kids, so he encouraged me to do this,” Zilis said in the book. Although Zillis initially planned on using an anonymous sperm donor, Musk later suggested that he could be the donor, which she agreed to.

“I can’t possibly think of genes I would prefer for my children,” Zilis said in the book.

Related: Elon Musk's Dating History: From Amber Heard to Grimes

Zilis welcomed twins Strider and Azure via in vitro fertilization around the same time Musk and ex Grimes — whose real name is Claire Boucher — were expecting their second child, according to the book.

In addition to Strider and Azure, Musk shares three children with Grimes and is also dad to 18-year-old twins Vivian Jenna Wilson and Griffin, along with triplets Kai, Damian and Sax, who were born in 2006, with his first wife, Justine Wilson. The two had another son, Nevada, who died at 10 weeks.

Never miss a story — sign up for PEOPLE's free daily newsletter to stay up-to-date on the best of what PEOPLE has to offer, from celebrity news to compelling human interest stories.

As noted in Isaacson’s book, Musk has long been concerned about the ongoing decline in birth rates across the globe.

The Tesla CEO has expressed his concerns in multiple posts on Twitter, now known as X. In July 2022, he claimed he was “doing my best to help the underpopulation crisis.”

“A collapsing birth rate is the biggest danger civilization faces by far,” Musk wrote at the time.

Musk reiterated his concerns on the social media platform more than a month-and-a-half later. “Population collapse due to low birth rates is a much bigger risk to civilization than global warming,” he suggested.

Related: Everything to Know About Elon Musk's Family (He's a Dad of 11)

Most recently, Musk welcomed his third child, a son named Techno Mechanicus, with his ex Grimes, according to The New York Times’ review of Isaacson's book.

The two are also parents to son X Æ A-12, whose name was later changed to X Æ A-Xii following his 2020 birth and is nicknamed “X,” and a daughter born via surrogate in December 2021 named Exa Dark Sideræl.

Related: Elon Musk’s Daughter 'Doesn’t Want to Spend Time with Me,' He Says in New Biography: Report

Although Musk is a proud father, in an interview with the Wall Street Journal’s CEO Council in May, he said he believes it would be "a mistake" to simply hand over his companies to his children.

“I am definitely not of the school of automatically giving my kids some shares of the companies, even if they have no interest or inclination or ability to manage the company,” he said at the time.

Simon & Schuster's Elon Musk by Walter Isaacson is due out Sept. 12, and is available for pre-order now.

For more People news, make sure to sign up for our newsletter!

Read the original article on People.