of the National Science Foundation estimated that in 1999, there were 955,300 biological scientists in the US (about 1/3 of who hold graduate degrees). There were also 152,800 earth scientists in the US as well. [ 137 ] A large fraction of the Darwin Dissenters have specialties unrelated to research on evolution; of the dissenters, three-quarters are not biologists. [ 138 ] As of 2006, the dissenter list was expanded to include non-US scientists. [ 139 ] Despite the increase in absolute number of scientists willing to sign the dissent form, and an increase in public support, proportionately the figures indicates the support from scientists for creationism and intelligent design is steadily decreasing. [ citation needed ] Some researchers are attempting to understand the factors that affect people's acceptance of evolution. Studies have yielded inconsistent results, explains associate professor of education at Ohio State University, David Haury. He recently performed a study that found people are likely to reject evolution if they have feelings of uncertainty, regardless of how well they understand evolutionary theory. Haury believes that teachers need to warn students how powerful, and thus misleading, "gut" instincts can be when they are trying to judge the rational merits of ideas. [ 140 ] [ 141 ] ^ Numbers, Ronald L. (2009). "Myth 24: That Creationism is a Uniquely American Phenomenon" . Galileo goes to jail and other myths about science and religion . Cambridge and London: Harward University Press. p. 217. ISBN 978-0-674-03327-6 . Retrieved 2011-09-03 . "Antievolutionists