The bitterness seems real:<p>&gt; The debate has clearly become acrimonious. Paap says that he has been ignored; Bialystok feels she is being personally attacked. Perhaps, wrote Eric-Jan Wagenmakers from the University of Amsterdam, the two sides could form an “adversarial collaboration.” That is, they would work together to test the bilingual advantage once and for all, through a large study, perhaps involving many labs. The teams would pre-register all their experimental plans and agree to publish the results no matter what, so there could be no accusation of questionable research practices or publication bias. Then let the chips fall where they may. This approach has already been used to some success in other areas of psychology.<p>&gt; Paap is up for it; Bialystok is not. “That’s not how science works: You don’t sign a contract to not change anything in your protocol as the research evolves,” she says. “And they’ve set up so many toxins in this area that no good collaboration can result.” Bak feels similarly. “How much would I win by working with someone who doesn’t understand the area and is already biased?”