A sociologist at Rutgers University questioned more than 150 scientists whose work was relevant to a 2003 political clash between several members of Congress, a Christian lobbyist group called the Traditional Values Coalition, and the National Institutes of Health (NIH).

Of the 112 scientists who responded, more than half said they have since self-censored their grant proposals to remove "red flag" words -- such as gay, lesbian, AIDS, needle-exchange or anal sex. Nearly a quarter of respondents said they either modified their studies to seem less controversial or abandoned controversial grant proposals.

At the time of the 2003 debate, members of Congress asked the NIH to explain the medical benefit of 10 government-funded studies some called inappropriate. However, a staffer accidentally sent the NIH a much longer list of 250 proposed "questionable" studies compiled by the Traditional Values Coalition. The NIH Director at that time, Elias Zerhouni, decided to review the full list of studies anyway. While no studies lost their funding because of their inclusion on the list, it is now apparent that scientists did indeed react to the controversy with self-censorship.