FORTUNE — In the weeks following the death of Apple’s CEO and co-founder one year ago today, more than a million people sent emails to an address set up by Apple (AAPL). Messages on blogs, Facebook (FB) and Twitter, and even makeshift in-store memorials, demonstrated a collective sadness at the Apple co-founder’s passing. And now, Memmento.com, a new online cemetery, has not one, not two, but three competing Jobs memorials. Why do so many people who never met the man care so much that he is gone?
Andrew Przybylski, a psychologist at the University of Essex, surveyed a few hundred Apple users about how their relationship with their devices informed their feelings about Jobs’ death. A third of the participants reported feeling emotionally connected to their Macs, iPads, iPhones and iPods, agreeing with the statement that the devices “occupy a special place in my heart” — and those people were 70% sadder about his passing than those who didn’t feel the love.
An idea called the self-determination theory used in education, sports, and gaming circles tells us that people become more psychologically involved when circumstances satisfy certain universal needs. Indeed, Przybylski found that people felt emotionally connected to their Apple gadgets — and by extension their creator — because the devices satisfied two of those needs, “relatedness” and “autonomy,” which, he says, “strike at the heart of the purpose of computing devices: to connect us to others and to provide us with meaningful choices.”
Beyond just putting technology in people’s hands, there’s something unique in Steve Jobs’ legacy. “I think that he delivered experiences that met and in many cases exceeded users expectations,” Przybylski says. “He gave generations of scientists, students, business people, and artists tools to go farther than they thought they could.”
A shorter version of this story appeared in the October 8, 2012 issue of Fortune.