was to carry out a randomised controlled trial. After recruiting voters
to participate in a series of surveys, LaCour would randomly split the
group. Some would get visits from a canvasser; others, acting as a
control group, would have conversations about recycling.
What happened next would reveal a lot about how beliefs change,
just not quite in the way we might expect. It started when LaCour
reported back with some remarkable findings. His trial had shown that
when interviewers used deep canvassing methods, there was a large
increase in interviewees’ support for same-sex marriage on average.
Even better, the idea often stuck, with the new belief still there
months later. This belief was also contagious, spreading to
interviewees’ housemates. LaCour and Green published the results in
the journal Science in December 2014, attracting widespread media
attention. It seemed to be a stunning piece of research, showing how
a small action could have a massive influence.[57]
Then a pair of graduate students at the University of Berkeley
noticed something strange. David Broockman and Joshua Kalla had
wanted to run their own study, building on LaCour’s impressive
analysis. ‘The most important paper of the year. No doubt,’
Broockman had told a journalist after the Science paper was
published. But when they looked at LaCour’s dataset, it seemed far
too pristine; it was almost as if someone had simulated the data
rather than collecting it.[58] In May 2015, the pair contacted Green
with their concerns. When questioned, LaCour denied making up the
data, but couldn’t produce the original files. A few days later, Green –
who said he’d been unaware of the problems until that point – asked
Science to retract the paper. It wasn’t clear exactly what had
happened, but it was clear that LaCour hadn’t run the study he said
he had. The scandal came as a huge disappointment to the Los
Angeles LGBT Center. ‘It felt like a big punch to our collective gut,’
said Laura Gardiner, one of their organisers, after the problems
emerged.[59]
Media outlets quickly added corrections to their earlier stories, but
perhaps journalists – and the scientific journal – should have been
more sceptical in the first place. ‘What interests me is the repeated
insistence on how unexpected and unprecedented this result was,’