why do some controversies persist - despite evidence?

physorg |  If you believe in evolution, then everything can be explained in evolutionary terms, whereas if you believe in creation, then everything is understood using different assumptions about how the world works.

In many controversies, the two sides operate from different assumptions and worldviews that are analogous to scientific paradigms. Any fact that doesn't fit into the standard picture is dismissed as an anomaly.

For example, pro-fluoridationists dismiss studies suggesting a link between water fluoridation and the crippling disease skeletal fluorosis.

Group dynamics

Campaigning groups can develop a sense of solidarity and community. They are advocating for a worthy cause, after all, and it feels good to be among like-minded people.

Most campaigners interact mainly with others on the same side, and seldom have dinner with bitter opponents.

Many years ago, when I interviewed leading scientists, doctors and dentists who were active and prominent in the fluoridation debate, it was obvious they identified with those on the same side and interacted with their opponents only in antagonistic forums such as debates.

Public scientific controversies are not just about the science. They invariably involve differences in values concerning ethics and social choices. Partisans will come at the issue with differing assessments of fairness, care, authority and sacredness.

In the fluoridation debate, the morality of caring for others is present on both sides. Proponents say fluoridation potentially benefits everyone, especially those who are too poor to afford good dental care.

Opponents care more about those who might be damaged by fluoridation, arguing against putting a medication in the water supply to treat the population, using an uncontrolled dose.

If
In many controversies, the two sides operate from different assumptions and worldviews that are analogous to scientific paradigms. Any fact that doesn't fit into the standard picture is dismissed as an anomaly.
For example, pro-fluoridationists dismiss studies suggesting a link between water fluoridation and the crippling disease skeletal fluorosis.
Group dynamics
Campaigning groups can develop a sense of solidarity and community. They are advocating for a worthy cause, after all, and it feels good to be among like-minded people.
Most campaigners interact mainly with others on the same side, and seldom have dinner with bitter opponents.
Many years ago, when I interviewed leading scientists, doctors and dentists who were active and prominent in the fluoridation debate, it was obvious they identified with those on the same side and interacted with their opponents only in antagonistic forums such as debates.


Read more at: http://phys.org/news/2014-08-controversies-persist-evidence.html#jCp