Two mice, one gene-altered and the other not, at the University of Pennsylvania School of Medicine. (David Howells/Corbis via Getty Images)

Americans divided over whether animals should be used in scientific researchThe U.S. public is closely divided when it comes to the use of animals in scientific research. Some 47% favor the practice, while 52% oppose it, according to a new Pew Research Center survey.

These findings are in keeping with a 2014 survey by the Center, which found similar results: 47% of Americans were in favor of using animals in scientific research, and 50% opposed it. The 2014 survey used somewhat different question wording and polling methods.

The latest survey results come at a time when the use of animals in scientific research continues to be a contentious issue that pits members of the scientific community against activists, and sometimes politicians, who say the practice is inhumane and unnecessary. Researchers, however, say the practice remains essential for developing treatments for diseases and conditions that include cancer, arthritis and HIV, and that they’re adhering to ethical guidelines.

As with the 2014 survey, there is a wide gender gap on this issue. A majority of men (58%) favor the use of animals in scientific research while just 36% of women say the same.

Those with a high level of science knowledge – based on a nine-item index – are more inclined to approve of animal use in scientific research. About six-in-ten (63%) favor the practice, compared with 44% of those with medium levels of science knowledge and 37% of those with low science knowledge.

Opinions on using animals in scientific research follow a similar pattern by general education level, which is closely linked with science knowledge. Those with a postgraduate degree (59%) are more likely to be accepting of the use of animals in scientific research than those with a high school degree or less (40%).

Unlike some science-related topics, notably climate change and environmental regulations, partisanship is not a factor for this issue. Half of Republicans and independents who lean Republican (50%) support the use of animals in scientific research, compared with 48% who oppose the practice. Similarly, 45% of Democrats and Democratic-leaning independents support the use of animals in scientific research, while 54% oppose it.

In March, President Donald Trump signed bipartisan legislation that limits the use of dogs in scientific research conducted by the U.S. Department of Veterans Affairs. The legislation was opposed by 40 scientific and medical groups, who argued that the research was helpful in developing human therapies.

Mark Strauss  is a former writer/editor focusing on science and society at Pew Research Center.