WASHINGTON: Americans are markedly more confident about the societal consequences of an ageing population than most people in the world, a major survey into global demographic trends has established.

According to the report, "Attitudes About Aging: A Global Perspective" from the Pew Research Center, only 26% of Americans believe that the growing number of older people is a "major problem" – a much lower proportion than in developed countries in Asia and Europe.

As the global population of people aged 65 and over is expected to triple to 1.5bn by 2050, respondents in East Asia emerged as the most concerned about the development.

Nearly nine-in ten Japanese (87%) agreed that a greying population will be a major problem, a view shared by 79% of South Koreans and 67% of Chinese respondents.

Over half of Germans and Spanish also expressed concern – at 55% and 52% respectively – while only Indonesians and Egyptians showed more optimism than Americans out of the 21 countries and 22,425 people covered in the survey.

Americans are also more upbeat than Europeans that they will maintain an adequate standard of living in their old age, leading the report to conclude that overall confidence in the US is based on the country ageing at a slower rate than others, largely because of its high rate of immigration.

In 2010, the global median age was 29 compared with the US median age of 37, but the gap is projected to narrow from eight years to five by 2050, by which time the US population is expected to grow by 89m while the populations of Japan, China, South Korea, Germany, Russia, Italy and Spain either decline or remain the same.

While the US population is set to grow substantially, Africa is expected to witness the highest level of population growth, with the addition of 1.4bn people by 2050.

Meanwhile, the population in Asia and Oceania is expected to grow by 1bn while, in sharp contrast, Europe's population will shrink by more than 30m people.

Data sourced from Pew Research Center; additional content by Warc staff