As we get older, we may be more inclined to think people look happy, a new study has found.
Scientists have found that ageing adults often show a 'positivity bias' when interpreting facial expressions, meaning they are more likely to label neutral or negative facial expressions as happy rather than sad or angry.
“This means they’re more likely to think that ambiguous or unclear expressions are ‘happy' rather than 'sad' or ‘angry,’" lead author Dr Noham Wolpe told BBC Science Focus. “Importantly, this bias was linked to both subtle cognitive decline and changes in specific brain circuits involved in processing emotions and decision-making.”
The team, working with data from more than 600 adults, used emotion recognition tasks alongside brain scans to probe the phenomenon.
They found structural differences in the hippocampus and amygdala – regions central to memory and emotion – as well as altered connectivity with the orbitofrontal cortex, which helps us weigh emotional information and guide decisions.
“These regions form a network crucial for interpreting emotional signals and guiding decisions,” Wolpe said, explaining how in adults experiencing cognitive decline, the connections between the orbitofrontal cortex and amygdala become stronger.
“This might make them more likely to interpret ambiguous or neutral emotional stimuli as positive, which we see as the positivity bias,” he said, adding that exactly why cognitive decline is linked to increased connectivity remains unclear.
While the research is still in its early stages, the implications are significant. Because emotional processing often changes before memory loss becomes obvious, positivity bias could one day be harnessed as an early warning sign for dementia.
“Although testing emotion recognition is not ready to replace existing cognitive tests, it might one day be combined with standard screening tools to improve early detection,” Wolpe said.
Wolpe and his colleagues have already begun exploring future methods, such as immersive virtual reality tasks, to capture how people naturally respond to emotional cues.
The next step will be to see whether this positivity bias actually predicts decline. The team has recently completed follow-up assessments of participants from the Cambridge Centre for Ageing and Neuroscience study, about 12 years after their original testing. They are also linking participants’ data with GP records to track dementia diagnoses.
“The key message,” Wolpe said, “is that our emotional responses, like subtle biases in how we see others’ expressions, may reveal early brain changes long before typical symptoms of dementia appear.
“Understanding these links could open the door to faster detection and, ultimately, earlier and more effective interventions.”
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About our expert
Noham Wolpe is a senior lecturer in the Sagol School of Neuroscience at Tel Aviv University. His research aims to understand the links between cognition, mental health, and action, both in health and disease.