Negative perceptions toward the elderly have been on a steady rise for the last 200 years, according to a new Yale study looking at over 400 million words in archives of American publications.

The study looked at historical usages of phrases describing the elderly, such as “senior citizen,” and analyzed the context of those words. Any descriptive terms within four words of the phrase were analyzed for their positive or negative connotations. Using a wide range of literature, newsprint and other media, the study then rated each year for its treatment of the elderly on a scale of one to five. The researchers found that over 200 years — starting in 1810 and ending in 2009 — American society’s conceptions of the elderly have steadily declined. While there were some fluctuations throughout time, Americans went from largely positive at the start to quite negative by the end.

“We looked at the context where the older person is described in the language,” said Becca Levy, professor of epidemiology and psychology at the Yale School of Public Health and the senior author of the study. “It could be looking at a variety of stereotypes, whether the old person is thought of as wise or cantankerous.”

The study found that the year 1880 was the important turning point in public perceptions of the elderly. In that year, representations of the elderly in the media transitioned from primarily positive to primarily negative.

According to Levy, this long-term degradation in favorable views of the elderly is explained through the increased treatment of age as a disability, as well as the simple increase in the number of older people. Increasingly, older people are seen as problems for doctors to solve, putting a burden on society.

“We thought that it was possible that as the number of older people increased that the misconception that there’s fewer resources to go around to older populations would build,” Levy said. “So that might lead to more fear and negativity.”

Another factor that may have led to the increase in negative perceptions is the synonymization of aging with medicalization and disability, said Joan Monin, professor of epidemiology at the Yale School of Medicine and one of the study’s co-authors. She added that, in order for the trend to reverse, the media has to change its portrayal of older adults.

Currently, children grow up seeing negative portrayals of the elderly on television and often internalize these biases, Monin said. Instead of seeing aging as a fundamental part of life, children learn from medication advertisements that aging is something to be fought with whatever pills are necessary to do the job.

When they grow up, she said, these adults see the elderly as a class to avoid or pity, which has a fundamentally harmful effect on the elderly.

“There’s not a lot of intergenerational contact between older adults and young adults,” added Monin. “Oftentimes older adults are segregated or put in retirement communities away from younger adults, and so more interaction between different age groups — especially in a family setting — is really important.”

The deleterious effects of ageism are not limited to hurt feelings, Levy said. Another of Levy’s studies demonstrated that senior citizens who are treated negatively live demonstrably shorter lives. If this is the case, then the increasingly poor perception of the elderly causes actual harm to some of the 36 million retired people receiving Social Security benefits in the U.S.

According to the Centers for Disease Control and Prevention, in 2012, there were roughly 43.1 million U.S. residents 65 and older.