The gender of a researcher conducting a study can skew the results, NPR reports. It adds that while this issue has been known for some time, researchers say it hasn't been well addressed.
The University of Uppsala's Colin Chapman tells NPR that a study in the 1970s found that IQ, which is thought to be relatively stable, would shift based upon the gender of the person giving the test: a female researcher testing a male participant would get a higher IQ score. Similar effects have also been noted in pain research, according to NPR adds. Chapman and his colleagues note in a review appearing in Science Advances, that the effect could be due to social pressures, such as a male heterosexual participant trying to impress a female experimenter.
Chapman's own work investigating whether an oxytocin nasal spray would curb obesity among men didn't have the results he expected — and the results another group found — because the spray was administer by two men and one woman, NPR notes. But the lab didn't track which investigator gave which study participant the spray, it adds.
Chapman and his colleagues argue that that has to change. "To improve the prevalence of experimenter gender reporting, first and foremost, individual scientists must take upon themselves the task of tracking and reporting their experimenter and/or research assistant genders going forward," they write.