 When we encounter unfamiliar and complicated information, we rely upon mental shortcuts to help us make sense of what we are seeing or hearing. Our brains begin to look for clues that help us evaluate the quality of the information quickly and efficiently. For instance, I might be more open to accepting new information if it comes from someone I trust, or if I hear the same thing repeated from several different sources. These mental shortcuts are called cognitive heuristic cues, and everyone uses them. Generally, heuristics aren't a problem. But sometimes, without us realizing it, they can cause bias against good information that doesn't satisfy our unconscious heuristic cues. This can be a big problem for public health communicators, especially when the heuristic cues that people use lead them to reject strong science and public health recommendations. In our research, we interviewed 27 Canadians to find out what heuristic cues they are using to make sense of changes to pandemic-related science. We asked, what sort of heuristic cues do people rely upon to make judgments about changing information about masks and vaccines? We found that people are very dependent upon expectancy heuristics when making sense of new information about masks and vaccines. This means that, whether or not someone expects scientific information to change over time, strongly affects whether or not they are willing to accept new scientific information. We also found that people are more resistant to the latest information about masks and vaccines when it conflicts with their past beliefs on these subjects. Understanding the role that expectancy heuristics play and how people make sense of scientific information can help public health communicators tailor their messages to the reasoning strategies of the public. Based on these findings, we make two recommendations. One, public health communicators should emphasize that science is constantly evolving to set the expectation that the best information could change in the future. Two, when changes do occur, public health communicators should acknowledge these updates rather than simply replacing old information with new information. Thanks for watching. Visit our channel to learn more about our research. And if you like this, please share it with your friends.