In a first for any age group, more than half of Americans age 25-29 live in households with cellphones but no traditional landline telephones.

A U.S. survey shows Americans are abandoning their landlines and adopting cellphones at a far greater rate than Canadians. (Matt Sayles/Associated Press)A report on phone use by the U.S. Centers for Disease Control and Prevention also found that the younger children are, the likelier they are to live in homes that only have wireless phones. That suggests that younger parents are showing increasing comfort relying only on cellphones even as they adjust from being single to a more settled family lifestyle, according to one of the report's authors.

Taken together, the figures released Tuesday provide the latest evidence of how young people are leading the evolution away from landline phones.

"You could say that among that age group, wireless only is the new norm," said Stephen Blumberg, a senior scientist at CDC and an author of the survey.

'Wireless only is the new norm'—Stephen Blumberg, CDC senior scientist

Canadian figures released Friday show the shift from landline to cell isn't as dramatic, although it is highly significant.

According to Statistics Canada, 77 per cent of Canadian homes have at least one cellphone. But the proportion of homes with landline service has dropped to 89 per cent, the lowest level since 1965.

The shift toward cellphones and away from landlines is having a wide impact, changing not only how people communicate but also the work of pollsters and others who collect data.

More than a quarter of U.S. homes have cell service only

The survey showed that overall, 27 per cent of U.S. households had only cellphones in the first half of this year, up two percentage points since the last half of 2009. That number has been growing rapidly — in the first six months of 2007, just 14 per cent of households relied only on wireless service, roughly half of current U.S. levels.

Producer, director and Order of Canada recipient Ivan Reitman speaks on his cellphone as he takes a walk through Yorkville at the Toronto International Film Festival. New figures show Canadians lag behind Americans in adopting cell phones over landlines. (Jonathan Hayward/Canadian Press)Among 25- to 29-year-olds, 51 per cent lived in homes with only cellphone service in the first half of 2010. That was up two percentage points from the previous six-month period.

For both age groups bracketing them — 18- to 24-year olds, and 30- to 34-year-olds — four in 10 lived in cellphone-only households. After age 35, the likelihood that people live in homes with only wireless service falls off, with only one in 20 people age 65 and up living in homes that rely solely on cellphones.

The study also found that among children under age three, nearly four in 10 live in wireless-only households. That figure drops to about a third of children age three to five, and less among older children.

Blumberg said this is significant because it counters the perception — backed by previous data — that cellphone-only households are likelier to be comprised of young, unattached people. The latest numbers suggest that as young people used to living only with cellphones have families, they're keeping their wireless-only habits.

"It's a sign that wireless-only is no longer strictly tied to a lifestyle of being young and restless," Blumberg said.

Many landlines simply used for internet connection

In addition to cell-only households, the survey found another 16 per cent of households have landlines, yet get all or nearly all their calls on their cellphones. Their landlines are usually hooked into computers.

This means that in order to call 43 per cent of U.S. households, the only practical way to do it is to dial their cellphones.

The study also found that:

• The households likeliest to rely only on wireless phones consist of adults who are poor, renters, or who live with unrelated housemates.
• Only 13 per cent of households have landlines and no cellphones — down from 24 per cent in early 2007.
• Though people age 18-29 are the heaviest cellphone users, they comprise only 40 per cent of all wireless-only adults. That's because young adults make up only about one-fifth of the total adult population.
• Only 16 per cent of Northeasterners live in cellphone-only homes, the lowest of any region. The highest frequency of wireless-only households is in the South, where 29 per cent live that way.
• About two per cent of households have no phone service at all, a figure that has changed little in recent years.

The data for the study was compiled in the National Health Interview Survey, conducted by CDC's National Center for Health Statistics. It is based on interviews with members of 17,619 households conducted from January through June this year.