The survey found that ageism now eclipses racism, sexism and discrimination based on disability.
The only group not to experience ageism are those people aged between 35 and 44 who are too old for negative youth stereotyping and too young for prejudice based on advancing years, the study found.
Among the 43 per cent of the participants of the survey of 1,843 people who said they had experienced prejudice of some sort, 65 per cent said it included first-hand experience of age discrimination, said Dominic Abrams, professor of social psychology at the University of Kent.
"Ageism is the form of prejudice that is experienced most commonly by people in the UK. It's the most pervasive form of prejudice; and that seems to be true pretty much across gender, across ethnicity, religion and disability - people of all types experience ageism," Professor Abrams told the Science Festival in Dublin. "Government legislation on equality and human rights needs to ensure that ageism is treated at least as seriously as all of the other forms of prejudice that it's tackling."
The study found that both men and women suffer ageism and that their experience of it was greater even than the sexism experienced by women. Younger people also felt discriminated against because of their youth, although discrimination against elderly people was more widely felt, Professor Abrams said.
"Age is in the eye of the beholder but age prejudice seems to be ubiquitous in British society.
"More youthful is seen as more useful," he said.
Those who took part in the study believed that older people are viewed as friendlier than younger people, while younger people were perceived as more competent and capable than older people.
Professor Abrams said combating age discrimination would become increasingly important as the average age of the British population increased.
* An expert on prejudice said Tony Blair's policy of promoting church schools was extraordinary given the experience of religious discrimination in Northern Ireland. "What we've experienced in Northern Ireland is that segregation in schools is not the cause of the conflict but it plays a role in maintaining the conflict," said Professor Ed Cairns of Ulster University.Reuse content