A new study by a University of British Columbia researcher finds that some people are genetically predisposed to see the world darkly.

The study, published in Psychological Science, finds that a previously known gene variant can cause individuals to perceive emotional events -- especially negative ones -- more vividly than others.

"This is the first study to find that this genetic variation can significantly affect how people see and experience the world," says Prof. Rebecca Todd of UBC's Dept. of Psychology. "The findings suggest people experience emotional aspects of the world partly through gene-coloured glasses -- and that biological variations at the genetic level can play a significant role in individual differences in perception."

The gene in question is the ADRA2b deletion variant, which influences the hormone and neurotransmitter norepinephrine. Previously found to play a role in the formation of emotional memories, the new study shows that the ADRA2b deletion variant also plays a role in real-time perception.

The study's 200 participants were shown positive, negative and neutral words in a rapid succession. Participants with the ADRA2b gene variant were more likely to perceive negative words than others, while both groups perceived positive words better than neutral words to an equal degree.

"These individuals may be more likely to pick out angry faces in a crowd of people," says Todd. "Outdoors, they might notice potential hazards -- places you could slip, loose rocks that might fall -- instead of seeing the natural beauty."

The findings shed new light on ways in which genetics -- combined with other factors such as education, culture, and moods -- can affect individual differences in emotional perception and human subjectivity, the researchers say.

Background

Further research is planned to explore this phenomenon across ethnic groups. While more than half of Caucasians are believed to have the ADRA2b gene variant, statistics suggest it is significantly less prevalent in other ethnicities. For example, a recent study found that only 10 per cent of Rwandans had the ADRA2b gene variant.

The study was co-led by UBC Prof. Rebecca Todd (as a PhD student at the University of Toronto) and Adam Anderson (Cornell University). DNA samples and genotyping were provided by Daniel Mueller (Toronto's Centre for Addiction and Mental Health).