Michael Kovac/Getty Images for Vanity Fair
- Walter Isaacson commended Elon Musk's engineering abilities, but suggested he lacks empathy.
- Isaacson made the comments on CNBC's Squawk Box, discussing his upcoming biography of Musk.
- Musk's manner has drawn more scrutiny amid mass layoffs at Twitter and his anti-trans posts.
Walter Isaacson, whose upcoming biography about Elon Musk is expected in September, said one of his takeaways from three years of observing the voluble executive is that he may lack empathy.
"I'm more impressed with him as an engineer," Isaacson said in an interview on CNBC's Squawk Box, which tweeted a clip of the segment on Monday. "I think that he does not have a fingertip feel for, you know, empathy, emotions."
It's an idea that Isaacson has broached before. In an interview on Twitter Spaces last month, he made a reference to Musk's "demon mode," suggesting that the trait, while intimidating to employees, was part of Musk's success. He had credited the pop star Grimes, Musk's ex-girlfriend who has two children with him, for that vivid characterization.
He repeated the idea on CNBC's Squawk Box.
"The question when you write a biography though, is how do you take the dark threads and realize that you can't just pull them out?" Isaacson said on the segment. "That he wouldn't be who he is without both, demon mode, and his drive."
In the segment, Isaacson also addressed recent headlines about Musk, including a purported cage match with Meta CEO Mark Zuckerberg. Isaacson reiterated his view that chatter of a physical rumble was merely a "metaphor" for the two executives' business rivalry. Meta's Twitter rival Threads amassed some 100 million users in days after its launch this month.
At one point, Isaacson also pushed back against a question about whether he tended to take a more lenient interpretation of Musk's remarks as a result of their time together.
"When you get up very close to a person as I have for the past three years with him, you understand that person," Isaacson said. "You understand the motivations," he said. "And there are a lot of faults," he added.
Musk's tenure at Twitter, which he took over in October, has been marked not only by the departures of high-level executives in key positions, but by massive layoffs. The company's headcount dwindled to about 1,000 employees, Insider's Kali Hays previously reported in May, down from about 7,500 before the Musk era.
Musk has also drawn scrutiny for posts wading into the culture wars targeting transgender people, saying even the mere prefix "cis", which refers to people identifying with the gender they were assigned at birth, could be deemed a "slur" on Twitter.
Musk has previously said he has Asperger's syndrome, an Autism spectrum designation that the Centers for Disease Control and Prevention says those who have it could "behave, communicate, interact, and learn" differently from others.
But experts have also cautioned against stereotypical assumptions about those with autism spectrum conditions when it comes to an individual's complex emotional capacities.
Emails sent to Musk's Tesla and SpaceX addresses did not receive a response on Monday morning. An email sent to Twitter's press address received an auto-reply that didn't answer the inquiry.