Maybe you've been told that you are too sensitive, or you know someone who has strong reactions to positive, negative, or intense experiences. Some people seem to be more sensitive than others, and new research has suggested that this trait may be genetic.
Twins that are raised in the same household experience mostly the same environment. Identical twins also carry the same genome, so twins can help researchers learn whether a trait is due to genetics - in which case a set of identical twins will both display the characteristic, or whether it's more likely to be related to environmental influences, and the trait will appear at similar rates in sets of identical and non-identical twins.
Researchers compared how identical and non-identical 17-year-old twins reacted to positive and negative experiences to gauge their level of sensitivity. The findings have been reported in Molecular Psychiatry.
"We are all affected by what we experience -- sensitivity is something we all share as a basic human trait," said the study leader, Michael Pluess, Professor of Developmental Psychology at Queen Mary University of London. "But we also differ in how much of an impact our experiences have on us. Scientists have always thought there was a genetic basis for sensitivity, but this is the first time we've been able to actually quantify how much of these differences in sensitivity are explained by genetic factors."
This study involved 2,800 twins: around 500 sets of identical twins and 900 sets of non-identical twins participated. About half of the twins were the same sex. They answered questionnaires designed by Professor Pluess that are meant to assess how sensitive an individual is to their environment. Later this month, the test will be freely available online, and you can gauge your own sensitivity level. The assessment is also meant to distinguish between sensitivities. Pluess is featured in the video below.
The research showed that environmental influences probably account for around 53 percent of a person's sensitivity levels, while genetics accounts for the other 47 percent.
"If a child is more sensitive to negative experiences, it may be that they become more easily stressed and anxious in challenging situations," said co-researcher Dr. Elham Assary. "On the other hand, if a child has a higher sensitivity to positive experiences, it may be that they are more responsive to good parenting or benefit more from psychological interventions at school. What our study shows is that these different aspects of sensitivity all have a genetic basis."
The scientists also found that there is a shared genetic component to sensitivity, extraversion, and neuroticism.
Professor Pluess believes the findings could help us in how we understand and handle sensitivity, in ourselves and others.
"We know from previous research that around a third of people are at the higher end of the sensitivity spectrum. They are generally more strongly affected by their experiences," Pluess said. "This can have both advantages and disadvantages. Because we now know that this sensitivity is as much due to biology as environment it is important for people to accept their sensitivity as an important part of who they are and consider it as a strength not just as a weakness."