"The thought process that went into building these applications, Facebook being the first of them ... was all about 'How do we consume as much of your time and conscious attention as possible?'" Parker said.
"And that means that we need to sort of give you a little dopamine hit every once in a while, because someone liked or commented on a photo or a post or whatever. And that's going to get you to contribute more content, and that's going to get you ... more likes and comments."
He described Facebook as ""a social-validation feedback loop" that is "exactly the kind of thing that a hacker like myself would come up with," because it exploits a psychological vulnerability.
Parker started out as a co-founder of the music-sharing site Napster before becoming involved with Facebook. His tenure at the social media site didn't last long; he was asked to resign in 2006 after police found cocaine in a vacation home he was renting.
Many media critics have begun arguing that the business model of Facebook and some other social sites encourages extremism, by creating echo chambers in which ideas spread without being contested, and by rewarding controversial ideas with greater exposure.
Questioning the role of social media
Parker is among a growing number of tech insiders whose consciences have begun to eat at them in the wake of the explosion of social media.
In a widely-shared post last year, former Google employee Tristan Harris outlined how tech companies capture the minds of users.
Product designers "play your psychological vulnerabilities (consciously and unconsciously) against you in the race to grab your attention," he wrote.
Like magicians, social media apps "give people the illusion of free choice while architecting the menu so that they win, no matter what you choose," he wrote.
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In an Atlantic article in 2014, programmer Ethan Zuckerman, the principal research scientist at MIT's Media Lab, apologized for his role in creating pop-up ads in the 1990s.
"I wrote the code to launch the window and run an ad in it. I'm sorry. Our intentions were good," he wrote.
But in his comments this week, Parker argued that the big brains behind big social networks knew exactly what they were doing when they developed their sites' advertising-based models.
"The inventors, creators — it's me, it's Mark [Zuckerberg], it's Kevin Systrom on Instagram, it's all of these people — understood this consciously. And we did it anyway," he said.
Parker described himself as a "conscientious objector" to social media, though he does maintain a presence on Facebook and Twitter.
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