{"id":43597,"date":"2018-05-07T15:09:02","date_gmt":"2018-05-07T22:09:02","guid":{"rendered":"http:\/\/world.edu\/?p=43597"},"modified":"2018-05-07T15:09:02","modified_gmt":"2018-05-07T22:09:02","slug":"good-science-doesnt-guarantee-public-acceptance-diverse-evidence-may-help","status":"publish","type":"post","link":"https:\/\/world.edu\/good-science-doesnt-guarantee-public-acceptance-diverse-evidence-may-help\/","title":{"rendered":"Good science doesn\u2019t guarantee public acceptance \u2013 diverse evidence may help"},"content":{"rendered":"

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\nIt takes more than just robust science to convince people to take on a certain point of view \u2013 consider topics such as\u00a0vaccination<\/a>,\u00a0genetically modified foods<\/a>\u00a0and\u00a0climate change<\/a>.<\/p>\n

Our recent\u00a0study<\/a>\u00a0looked how at the balance of evidence can shape the likelihood that people are convinced by it \u2013 and in particular how a psychological phenomenon known as \u201cthe diversity effect\u201d plays out in assessing scientific evidence.<\/p>\n

Here\u2019s an example of the diversity effect \u2013 consider the following two arguments. (A bit of information first: a sesamoid bone is a bone embedded in a tendon or muscle \u2013 but you don\u2019t need to know this to follow these arguments).<\/p>\n

Argument 1<\/strong>\u00a0\u2013\u00a0Sparrows<\/em>\u00a0have sesamoid bones.\u00a0Robins<\/em>\u00a0have sesamoid bones. Therefore, all birds have sesamoid bones.<\/p>\n

Argument 2<\/strong>\u00a0\u2013\u00a0Sparrows<\/em>\u00a0have sesamoid bones.\u00a0Penguins<\/em>\u00a0have sesamoid bones. Therefore, all birds have sesamoid bones.<\/p>\n

You find the second argument more convincing, right?<\/p>\n

This preference is the\u00a0diversity effect<\/a>. It\u2019s where people believe that conclusions supported by \u201cdiverse\u201d evidence (that is, evidence from very different sources) are more persuasive than conclusions supported by non-diverse evidence.<\/p>\n

Sparrows and penguins are very different, so it stands to reason that something that\u2019s true of both may be true of all birds. By comparison, sparrows and robins are pretty similar in other respects, so things that are true of them may not generalise to lots of other birds.<\/p>\n

When evidence gets complex<\/strong><\/h4>\n

Existing studies<\/a>\u00a0of people\u2019s reasoning have focused on simple arguments like the ones above. But many consequential real-world arguments, such as those from the sciences, are more complex.<\/p>\n

Evidence can be gathered using different measurement tools, or different experimental designs. Even conclusions based on a single measurement can be supported by evidence from different sources.<\/p>\n

Consider the case of climate change: evidence such as temperature readings can be drawn from different geographical locations, or from different time periods.<\/p>\n

While having many different kinds of evidence supporting a scientific argument strengthens it in the eye of the scientist, how can we communicate the strength of scientific theories to the general public?<\/p>\n

We know from the recent history of climate science communication that having a strong, well-supported theory\u00a0doesn\u2019t necessarily<\/a>\u00a0translate into strong public belief in that theory.<\/p>\n

Yet public acceptance of climate science is important as we need public support to ensure that effective policies are put in place to mitigate climate change.<\/p>\n

So perhaps we can turn to the cognitive psychology literature to help us find simple and effective ways to present scientific arguments to non-experts.<\/p>\n

This brings us back to the diversity effect. We wanted to see whether the diversity effect also holds for non-expert evaluation of real-world scientific arguments.<\/p>\n

Our Study<\/strong><\/h4>\n

We examined<\/a>\u00a0whether lay people used evidence diversity to reason about arguments in two domains where science has an important role in informing public policy: climate science and public health.<\/p>\n

We manipulated whether the evidence presented to lay reasoners (people with little formal training in either discipline) differed on a number of characteristics:<\/p>\n