Films are perpetuating harmful and out-of-date sexual, racial and gender stereotypes, according to the biggest-ever study of its kind into cinema audiences' opinions.

Of 4,315 adults across the UK who were surveyed, a clear majority believe cinema too often falls back on discredited stereotypes, including sexless older women, drug dealing, oversexualised black people and gay people whose lives are dominated by their sexuality.

Almost two-thirds of those questioned believe older women are "significantly underrepresented" in films. They are rarely portrayed as sexual beings and are, generally, only given marginal roles, according to the findings, published exclusively in the Guardian today.

Respondents said film-makers needed to try harder to create films which authentically reflected their lives.

"The film industry is made up of small companies who work in an isolated fashion. They don't have the money to carry out the research into who their audiences are and what those audiences want: that's what this survey is for," said Mary FitzPatrick, head of diversity at the UK Film Council, which commissioned the research.

The survey results pointed to Meryl Streep in Mamma Mia! as a positive example of an older woman shown embracing life. Characters such as Dame Judi Dench in Notes on a Scandal, however, were criticised for being too negative.

"Contrary to what one would expect, older women are increasingly comfortable with the 'cougar' image: they feel it signifies renewed interest and admiration for this age group," said Steve Evans, research director of Harris Interactive and author of the report, pointing to Melissa Leo, who won the supporting-actress Academy Award for her role as a domineering matriarch in The Fighter.

But Ariel Levy, author of Female Chauvinist Pigs, said the structure of films made it "almost impossible" to show nuanced, accurate portrayals of women. "Films are very formulaic and straitjacketed," she said. "Films are fairytales that, unless they have an unusually politically astute and creatively imaginative director, need to fall back on often insulting gender and racial archetypes to generate the energy necessary in the short amount of time they have."

Shirley Conran, author of Superwoman, said she had long given up expecting films to portray older women in anything other than a "grotesque" way. She agreed with Levy that the problem was inherent in the film industry. "They always say there are no good parts for women but there are lots of stories with great female characters. I have written some of them myself, and had them optioned by film companies," she said. "The problem is that the money men won't let those films get made because they underestimate audiences."

The study, Portrayal vs Betrayal?, also found half the population believe black characters are too often portrayed as drug dealers in films. Two in five say black characters don't get enough "good guy" roles, while one in three say black people are too often portrayed as being overly sexual.

This view is felt even more intensely by the black community itself: four out of five members of the black audience say black characters are too often portrayed as drug dealers. Three out of four say they are not portrayed positively enough. Two out of three say they are too often shown as overly sexual.

This is England attracted particular criticism as "irresponsible film-making that suggests racism is OK".

"There is a general consensus that black people are underrepresented in UK cinema and where they are featured it tends to be in a negative light," said Evans.

"The overwhelming view is that black people are generally portrayed as drug dealers, wearing hoodies, actively involved in gangs and living in sink estates. They rarely have regular, professional jobs."

Heavy criticism is made of TV programmes, including EastEnders, Coronation Street and Shameless. Films including Adulthood and Kidulthood were singled out as painting the most stereotypical pictures of multicultural youth and black people in particular.

"There is nothing inspiring about these films and they do nothing to suggest to people that they can get out of the situation they are in," said Evans.

Two in five of respondents agree that characters from ethnic minorities are often cast in films as a token gesture. Half of those aged 16 to 24 agree with this.

One in three say roles for minority groups too often have little depth and are poorly written. Just under half believe that Asian characters are too often portrayed as having family conflicts. More than half of the younger age group agree with both these statements.

Stories focusing on the working classes were too often depressing, according to over half the general population, with one in three believing the portrayal of the middle class is too "sweet".

Eastern Europeans are shown as being ill-educated and at the bottom of the economic ladder – a new potential stereotype.

Two in three of respondents agree that gay characters are too often portrayed with sexual orientation as their main trait.

Three in five say they are too often shown as being "camp". Among the gay, lesbian and bisexual population, those views are held by four out of five people.

"Film is often two large strides behind TV in terms of advancing positive depictions of lesbian and gay people," said Ruth Hunt, Stonewall's Director of Public Affairs. "Films rarely incorporate positive lesbian and gay characters and storylines."

Evans said the research pointed to "societal disconnect" with the gay audience.

"While UK society claims not to be homophobic, in reality gay men feel society is not comfortable with seeing open homosexual relations on screen," he said.