Despite its successes, science's reputation is shaky. Why?

It’s tempting for me to assign blame outside science. A news media that sensationalizes and oversimplifies science bears some responsibility. Also, scientists face formidable critics. Political, business and religious leaders attack scientific conclusions that they don’t like, while postmodern academics challenge the philosophical underpinnings of science.

But science’s credibility problems ultimately stem from the failures of scientists to explain our work in the public sphere. These failures sow distrust among the public and make us vulnerable to attacks by our critics. Some of science’s communication woes arise inevitably from our methods and results. Other difficulties are self-inflicted and therefore avoidable.

Scientists face the uphill battle of explaining results that are often counterintuitive, probabilistic or unpopular. We ask people to accept some rather outrageous stuff: that all the matter in the universe was once compressed into a tiny singularity, that the Earth is warming even though Boston got seven feet of snow this year, that injecting children with pieces of pathogens will prevent disease and that humans share a common ancestor with not only chimpanzees but also worms, bugs and slugs.

Further, because scientific results are frequently statistical, we often can’t deliver the personalized predictions that people crave. Let’s face it, parents want to know whether their child will get sick, not whether a vaccine is 97 percent effective. And to make matters worse, scientists often bear unpleasant news. Explaining climate modeling, evolutionary biology or nutritional science becomes doubly difficult when the message challenges people’s financial well-being, religious beliefs or breakfast routine.

While the nature of scientific results makes it hard for scientists to communicate to the public, our methodology generates even stiffer challenges. Although science produces highly reliable conclusions, it rarely takes a straight path to them. Contradictory results often arise when scientists repeat, extend and apply the work of others. Moreover, because scientists hold their ideas tentatively, our understanding evolves as new information emerges.

Examples from nutritional science illustrate this point. One study finds that drinking red wine is good for you; another one finds no benefits. And never mind, scientists tell the public, butter isn’t so bad for you. In fact, it’s the new health food. Ditto for egg yolks and dark chocolate.

Doing science is a little like making sausage — the product can be superb even when the process is ugly. And science cannot hide its process. Indeed, scientists must share their findings in order for them to be tested by others. But when people hear about one study after another, it’s a bit like tasting each ingredient separately rather than eating a finished sausage. To make science’s occasional flip-flops easier for the public to swallow, scientists must be honest about the limitations of their own work. When we do so, science’s course changes look less like blunders and more like a healthy process at work.

So far, we’ve been examining intrinsic features of science that complicate our communications to the public. Other issues arise when scientists fail to live up to our own ideals. Sometimes we allow our biases or egos to influence our science. Infrequently, we commit outright fraud. While such lapses can undermine the public’s confidence in science, they are also an opportunity for scientists to emphasize the vigor of our approach. When scientists repeat and extend the work of others, subjectivity gets offset and fraud gets detected.

Finally, scientists self-inflict damage to our credibility when we make claims beyond science’s scope. For example, when high-profile scientists make pronouncements about God’s existence (or non-existence), they make new enemies for science and create doubt about the validity of legitimate scientific conclusions.

Though scientists face unavoidable difficulties when publicizing our work, we can take steps to improve our credibility. Paradoxically, we must emphasize features of science that appear superficially to be weaknesses: the tentativeness of scientific conclusions, the limitations of individual studies and the restricted scope of scientific authority.