That is the subject of a recent open access PLOS paper:
Abstract: Christians are one of the most underrepresented groups in science, and one potential explanation is that scientists have a bias against Christian students, which could discourage and actively prevent Christian students from becoming scientists. Although there is a general perception in society that there is bias against Christians in science, we do not know whether science students, who frequently interact with scientists, perceive this bias. Further, no researchers have attempted to experimentally document the existence of bias against Christians in science. To address these gaps in the literature, we designed three studies. In the first study, we found that college science students report a perceived bias against Christians in science and that evangelical Christians perceive greater bias than Catholic and non-Christian students. Then in two studies, biology professors evaluated Ph.D. program applicants and we examined whether the professors rated a student less favorably when the student revealed a Christian religious identity. We found no statistically significant differences in how biology professors rated a student who was President of the Christian Association compared to a student who was President of the Atheist Association or a student who was President of the Activities Association. However, in Study 3, biology professors did rate a Christian student who went on a mission trip with Campus Crusade for Christ as less hireable, less competent, and less likeable than a student who did not reveal a Christian identity. Taken together, these studies indicate that perceived bias against Christians in science may contribute to underrepresentation of Christians but actual bias against Christians in science may be restricted to a specific type of Christianity that scientists call fundamentalist and/or evangelical.Are scientists biased against Christians? Exploring real and perceived bias against Christians in academic biology M. Elizabeth Barnes, Jasmine M. Truong, Daniel Z. Grunspan, Sara E. Brownell, Published: January 29, 2020
Note: “Taken together, these studies indicate that perceived bias against Christians in science may contribute to underrepresentation of Christians but actual bias against Christians in science may be restricted to a specific type of Christianity that scientists call fundamentalist and/or evangelical.” Well, Christians pay taxes for science and it’s really up to them to launch actions against actual bias incidents. No?
Some of us recall that U Kentucky had to pay astronomer Martin Gaskell $100k because he was passed over for a position he was well qualified for. It turned out that a colleague in the department had been communicating with a Darwin-in-the-schools lobbyist who identified him as some kind of a threat on account of his association with a Christians in astronomy group. If everyone this kind of crap happens to started demanding that the crap dumpers pay for the privilege, it could raise the cost of acting on the basis of scuttlebutt and prejudice.