The vast, stubborn discrepancy in Internet use between the generations adds up to one of the greatest ironies about social networking sites like Facebook: the people who would most benefit from keeping in touch with friends and family online are the least likely to have the tools to do so.

That contradiction was confirmed in a recent study by the Pew Research Center, which found that only 15 percent of people 75 and older use social media. Connected Living, a company based in Quincy, is trying to change that by installing easy-to-use Internet portals in group homes catering to senior citizens. So far, it’s been a resounding success: In the 200 retirement centers where Connected Living has a presence, seniors who were once intimidated by technology are using computers to reach out to their grandchildren. And because the program allows users to see the profiles of other residents of their buildings, some are even making new friends with strangers who live just down the hall.

By limiting access to seniors and their families, and creating an interface that seniors find easy to use, Connected Living has eliminated the biggest barriers that keep seniors from sites like Facebook or Twitter. That points to a lesson some other technology companies should keep in mind: By adapting Internet products to the needs of older people instead of expecting them to adapt to new technology, entrepreneurs can reach a whole new population — and enhance its quality of life.