A new report by the animal rights group PETA and Western Governors University indicates that Americans have a "growing opposition" to animal testing.

Presenting their findings Monday at the annual meeting of the American Association for the Advancement of Science in Chicago, the researchers contend that more than half of American women and young adults believe medical testing on animals is "morally wrong."

To reach their conclusions, PETA and WGU researchers assessed data collected from independent Gallup polls from 2001 to 2013. In each of the polls, approximately 1,000 Americans were asked if they found medical testing on animals to be "morally acceptable" or "morally wrong."

The analysis revealed a 12 percent increase between 2001 and 2013 in the number of survey respondents who found animal testing to be morally wrong. Overall, 41 percent of adults surveyed said they believed animal testing was morally wrong.

Thirty percent of men opposed animal testing in 2013, the analysis revealed.

That figure was elevated to 52 percent when accounting only for women and 53 percent when accounting only for people aged 18-29.

Across all political affiliations, opposition to animal testing increased since 2001, the study found.

"Opposition to animal testing is steadily rising among people of every gender, age group, and political affiliation, likely because people have more exposure than ever to information about the cruelty that animals endure in laboratories, how animal testing rarely helps humans, and the superior alternatives available," said study co-author Justin Goodman, a director at PETA and an adjunct instructor of sociology at Marymount University in Arlington, Va. "Now, the country's laws and policies governing animal experimentation and its research funding practices need to evolve to meet public expectations as well."

According to Human Society International, the number of animals "bred, injected, infected, cut open, genetically altered, and more, in the name of science" exceeds 100 million annually - more than three every second.

Many life-saving treatments and techniques have been pioneered through animal testing, and many scientists agree that animal testing is necessary, reservations aside.

A 2011 study published in the journal Nature revealed that 90 percent of the 1,000 biomedical scientists surveyed said that they thought the use of animals in research was essential. But 16 percent of those in agreement reported misgivings about using animals for research.