- Elon Musk's biographer says Musk "is a person with multiple moods and modes and personalities."
- Walter Isaacson told The Atlantic that Musk's many personalities are "quite vivid and different."
Elon Musk's biographer Walter Isaacson said he thinks the billionaire has multiple distinct "personalities" that come out in different situations.
"There are multiple Elon Musk personalities, and there are times when he's just brutal, times when he's got an epic sense of himself—which is both frightening and inspiring all at once—and times when he's an incredibly focused engineer," Isaacson told The Atlantic in an interview published on Monday.
"One of the exciting challenges is navigating the many Elon Musks, which, unlike anybody else I've written about, are quite vivid and different," the author continued.
Isaacson told The Atlantic that he felt Musk's involvement with Twitter has been "really problematic," but his work with electric vehicles through Tesla has been "actually quite helpful."
"This is a person with multiple moods and modes and personalities, ranging from engineering mode to demon mode," Isaacson told The Atlantic. "At times, he can be reckless and even dangerous. And at times, he can do some pretty amazing things."
Isaacson is no stranger to profiling powerful men. The writer has penned biographies of Steve Jobs, Albert Einstein, and Leonardo da Vinci. Isaacson previously said that he spent three years observing Musk as part of the writing process.
"When you get up very close to a person, as I have for the past three years with him, you understand that person, you understand the motivations," Isaacson told CNBC in July.
"And there are a lot of faults," he added.
A representative for Musk did not immediately respond to a request for comment from Insider sent outside regular business hours.