Rebecca Todd, from the University of
British Columbia, who led the research, said it supported the idea that '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'.
showed 207 healthy college-aged volunteers a series of positive, negative or
neutral words in rapid succession. Study participants were asked to type words
that they remembered onto a computer.
who carried the ADRA2b deletion - a genetic variant known to be linked with
susceptibility to intrusive traumatic memories - were more likely to recall negative
words than others. This association remained after researchers controlled for
sex, working memory, anxiety, depression and history of childhood abuse.
gene influences the hormone and neurotransmitter noradrenaline. The deletion
variant - present in around half of the study participants - is found in over half
of caucasians but is significantly less prevalent in other ethnicities.
Todd commented: 'These
individuals may be more likely to pick out angry faces in a crowd of people.
Outdoors, they might notice potential hazards - places you could trip, loose
rocks that might fall - instead of seeing natural beauty'.
researchers say their work is an attempt to unpick how genetics, combined with
cultural background and life experiences, shape individual differences in
emotional perception. 'For
a long time we'd look at cognitive processes as if they're universal', Professor Todd told
the National Post. 'Now
there's a lot more data coming out saying they're influenced by many things'.
is early to foresee any clinical implications of the study, the researchers say
that the bias towards negative stimuli for ADRA2B deletion carriers may help predict
increased vulnerability to post-traumatic stress disorder.
The study was
published in the journal Psychological Science.