Influential Paper on Gay Marriage Might Be Marred by Fraudulent Data

Harsh scrutiny of an influential political science experiment highlights the importance of transparency in research.


The paper, from UCLA graduate student Michael LaCour and Columbia University Professor Donald Green, was published in Science in December 2014. It asserted that short conversations with gay canvassers could not only change people’s minds on a divisive social issue like same-sex marriage, but could also have a contagious effect on the relatives of those in contact with the canvassers. The paper received wide attention in the press.

Yet three days ago, two graduate students from UC Berkeley, David Broockman and Joshua Kalla, published a response to the study, pointing to a number of statistical oddities, and discrepancies between how the experiment was reported and how the authors said it was conducted. Earlier in the year, impressed by the paper findings, Broockman and Kalla had attempted to conduct an extension of the study, building on the original data set. This is when they became aware of irregularities in the study methodology and decided to notify Green.

Reviewing the comments from Broockman and Kalla, Green, who was not involved in the original data collection, quickly became convinced that something was wrong – and on Tuesday, he submitted a letter to Science requesting the retraction of the paper. Green shared his view on the controversy in a recent interview, reflecting on what it meant for the broader practice of social science and highlighting the importance of integrity in research.

Political Scientist Chris Blattman also weighed in, arguing that – in a sense – discoveries of scientific misdoings were a sign that social science research was becoming increasingly transparent, with scholars opening up their work for others to check upon.

LaCour & Green’s case has received wide media attention. We should be careful, as a community of scholars whose work has a direct impact on public opinions, not to make hasty conclusions before full clarity on the incident is reached. We look forward to keeping you informed in the coming weeks as we learn more about the story.