Happy people's brains seem to respond better to strong positive things in their environment than others, thus clarifying the reason for some folk seem wear rose-tinted spectacles, new study found.
The scientists from Ohio State University said brain scans of volunteers who scored high on a standard test for happiness showed activity in regions that reinforced their happy dispositions and set them up for a "cycle of positivity".
Psychologists Wil Cunningham and Tabitha Kirkland at Ohio State University uncovered the effect while scanning the brains of 38 volunteers as they looked at a series of pictures designed to evoke positive, negative or neutral feelings.
The scientists focused on part of the brain called the amygdala, an almond-shaped region used in early processing of information about the world around us, and emotional reactions to it.
The scans showed that all the volunteers' brains reacted the same way to negative and neutral images, with negative pictures causing more arousal in the amygdala than neutral ones.
But the most striking result was that when the happiest volunteers, who had scored five and above on a seven-point happiness test saw positive images, the activity in their amygdalas rose much higher than it did in the less happy people.
"People with rose-tinted glasses are more responsive to positive things in the environment. But it's not at the expense of the negatives in life. They're not seeing the positives in everything, but they see the positives where they can find them," the Guardian quoted Dr Cunningham as saying.
"They extract both types of meaning from the world and probably have a better life because of it," her added.
The findings were reported at the Society for Neuroscience annual meeting in Washington DC.