By Christian Jarrett

It’s widely accepted children’s development reflects an interaction between their genes and the environment they are raised in. More tentative is the intriguing idea that the role of the environment is more consequential for some children than others. According to this view, a minority of children are environmentally sensitive “orchids” who suffer disproportionately in adversity, but who especially thrive in positive conditions.

To date, research into this idea has been stifled by the lack of a short, reliable test of children’s Environmental Sensitivity. As reported in Developmental Psychology, a team led by Michael Pluess at Queen Mary University of London has now developed a 12-item scale for this purpose. Preliminary work using the test supports the importance of the Environmental Sensitivity concept and suggests children fall into three groups: orchids; dandelions, who are relatively unaffected by the environment; and tulips, who are midway between the two.

The researchers started by asking over 300 children aged 11 to 14 years, at a school in East London, to complete an established adult measure of Environmental Sensitivity. Based on the children’s answers, the researchers removed unnecessary items and whittled the measure down to create a “Highly Sensitive Child” (HSC) test that asks children to rate how strongly they agree with the following items:

I find it unpleasant to have a lot going on at once

Some music can make me really happy

I love nice tastes

Loud noises make me feel uncomfortable

I am annoyed when people try to get me to do too many things at once

I notice it when small things have changed in my environment

I get nervous when I have to do a lot in little time

I love nice smells

I don’t like watching TV programs that have a lot of violence in them

I don’t like loud noises

I don’t like it when things change in my life

When someone observes me, I get nervous. This makes me perform worse than normal

Next, the researchers put their new test through its paces, by giving it, together with other personality measures, to 258 more children, aged 11-12 years, also at a school in East London; to 104 children (aged 8-11 years) at two London primary schools, who took the new test twice, several weeks apart; and to nearly 1,500 teenagers from across England and Wales, aged 15-19 years.

Data from these tests showed that like the adult version of the test, the new test appears to tap three separate factors (Aesthetic sensitivity; Ease of Excitation; and Low Sensory Threshold) that correlate and contribute to a general trait of Environmental Sensitivity. Importantly, Environmental Sensitivity appeared to be distinct from other traits already established in psychology, such as trait Neuroticism (or emotional instability). There was also notable stability in their Environmental Sensitivity scores when children took the test twice, weeks apart.

In a final analysis, the researchers combined all their data and looked to see whether the distribution of Environmental Sensitivity scores supported the idea that a minority of children are orchids, while the majority are “dandelions” and less sensitive to the environment, positive or negative. In fact, the new data suggested that scores tend to fall into three groupings, with roughly 30 per cent of children matching the environmentally sensitive “orchid” category, 30 per cent being “dandelions” and showing a distinct lack of Environmental Sensitivity, and the remainder being “tulips”, midway between the two other groups.

More research is need to test the reality of these categories and how they differ from each other, or whether it might actually be more accurate to see variation in Environmental Sensitivity as an unbroken continuum. It will also be interesting to see whether and how patterns of Environmental Sensitivity vary across cultures, and what are the factors that influence a child’s score on the test.

What’s already exciting from a practical and theoretical perspective, though, is that early research (conducted separately from the current study) using the new Highly Sensitive Child test, suggests that Environmental Sensitivity is a meaningful concept with important implications. For instance, a long-term study in the US of juvenile offenders (currently unpublished) found that risk of re-offending was more strongly related to quality of the home environment, good and bad, among those who scored high on Environmental Sensitivity. Similarly, another study found that both positive and negative parenting styles were more consequential for children rated higher by their parents on Environmental Sensitivity (using an adapted version of the new HSC test).

“Environmental Sensitivity is an important individual characteristic that is related to, but largely distinct from, other common temperament and personality traits,” the researchers said. “The current study suggests that it is possible to measure Environmental Sensitivity reliably in children and adolescents with the Highly Sensitive Child scale, a 12-item self-report measure with good psychometric properties.”

— Environmental sensitivity in children: Development of the Highly Sensitive Child Scale and identification of sensitivity groups

Christian Jarrett (@Psych_Writer) is Editor of BPS Research Digest