(Inside Science) -- Violinists were able to play together and stay in sync even when scientists played tricks on them during experiments. The musicians' capabilities may shed light on how people synchronize other kinds of behavior as well, a new study finds.
The capacity for groups to act in sync is seen among everything from subatomic particles to planets, from cells to crowds. Understanding the ways in which people can synchronize is essential "for understanding decision-making in groups, which is a wide subject related to economics, politics, human sciences and more," wrote study senior author Moti Fridman, a physicist at Bar-Ilan University in Ramat Gan, Israel, in an email. Previously, he investigated the synchronization of lasers and that of singing wineglasses.
Other researchers have explored the ways people synchronize, including in situations such as pedestrians on bridges and brokers in stock markets. However, this prior work mostly focused on simple networks where everyone was connected to everybody else, as opposed to more complex networks where each person might have connections to a varying number of others. It also had limited control over many aspects of these networks, such as whether there were delays in messages sent between people.
In the new study, Fridman and his colleagues analyzed how well professional violinists could synchronize. They asked musicians to repeat the same musical phrase, without being able to see or listen to each other apart from what they heard over noise-canceling headphones. The researchers could adjust the amount of delay in what the violinists could hear from other players, and they repeated the experiments using different combinations of violinists and with varying delays.
The scientists found the violinists could quicken or slow their tempo by a factor of three to synchronize with others. They also discovered that individual players could ignore "frustrating signals" -- for example, if another violinist was playing at a different tempo compared with the rest of the group -- to achieve synchrony.
"The ability of humans to ignore frustrated signals changes completely the dynamics of human networks beyond what was predicted by network models until now," Fridman wrote in an email. We are familiar with how people can ignore distractions -- for instance, the ability to listen to one companion amid other conversations during a cocktail party -- "but until now, all models for human synchronization did not consider this ability," he wrote.
Applied mathematician Steven Strogatz at Cornell University, who did not take part in this research, noted he and his colleagues previously tried similar experiments with crickets in soundproof boxes, but they proved challenging to experiment with -- one year, a virus killed them all off. "The great thing is that they've done the analogous experiment with people," Strogatz said. "This is a stimulating initial foray into finding the rules that underlie synchronization in complex human networks."
Experimental research into how synchronization works has lagged behind theoretical work "for decades, and so the theoretical work may be going in completely the wrong direction," Strogatz said. "We're finally getting some feedback from experiment to theory, the way science is supposed to work."
This work can be beneficial to understanding how and when a group of people in a social network that is exposed to false information can jump to wrong conclusions, according to Fridman. "This can prevent what is known as 'fake news' to spread without control," he wrote.
In addition, such research may help lead to ways to better understand epidemics and prevent them from spreading, according to Fridman. Strogatz noted that delayed interactions within complex networks, such as those examined in this study, are also problems with the COVID-19 pandemic -- for instance, the delays seen between when someone is infected and when they show symptoms, or between when someone gets tested and when they get results.
"Our results are also related to any network where each node in the network has decision-making ability, such as autonomous cars, or introducing AI into our highly connected world," Fridman wrote. "Our model can predict with high accuracy the dynamic of such systems, beyond what was possible before."
The scientists would now "like to extend our experiment over the Internet to try to measure the dynamic of hundreds and thousands of violinists," Fridman wrote.
The researchers detailed their findings online Aug. 11 in the journal Nature Communications.