Environmental sensitivity is the ability to register and process external factors, explained by professor Michael Pluess in his 2015 paper on the subject. Humans can differ substantially in the degree they respond to developmental contexts, with some being more sensitive to environmental influences than others. Michael Pluess will be a keynote speaker at the 2019 ESCAP meeting in Vienna. He spared some time to talk to ESCAP about sensitive children and their environmental influences.
What does environmental sensitivity mean?
“Environmental Sensitivity is an important basic trait which allows an individual to adapt to their environment. It is the precondition for the ability to adapt. If someone can’t sense the environment and doesn’t perceive specific details of the environment, then he will also not be able to process and adapt to those aspects of the environment. However, most people show a significant degree of sensitivity, but there are individual differences, with some being more sensitive than others”.
How do you go about measuring sensitivity?
In their recent 2018 paper
, Pluess and colleagues offer a detailed explanation of the new Highly Sensitive Child (HSC)
a self-report questionnaire to measure environmental sensitivity. “We have put a lot of effort into the development and validation of this measure. The 12-item HSC scale allows us to measure environmental sensitivity in children from about 8 years and older. It draws on 38 sensitivity items for children, adapted from the 27 items included in the Highly Sensitive Person
scale for adults. In addition, we have recently also developed a behavioural rating scale for children as young as 3 years, which is made up of standardised video sequences that we rate for sensitivity behaviours. We are currently also piloting a teacher rating scale, which we will validate in a longitudinal study in the Swiss-Italian region later this year”.
Early development and environmental sensitivity
“Sensitivity is a temperament trait. Like most common traits it is a dimension, not a diagnosis or a clinical syndrome. Although children that are more sensitive are more likely to suffer if they experience adverse events. However, being highly sensitive doesn’t require treatment. Sensitive children can thrive in positive environments and even outperform less sensitive children. I think it’s important for parents, teachers as well as children to be aware of the child’s environmental sensitivity and have an idea of the ideal environment for the child. In many cases, it is useful to develop coping skills to deal with over-stimulation, for example”. In fact, when children undergo cognitive behavioural therapy it is the more sensitive children that seem to benefit the most. “My interpretation of this finding and observations from other studies is that sensitive people may process things more deeply and they are also more conscientious, they get stuck into something and want to understand and think things through. Perhaps that way they are more likely to acquire coping skills or techniques that are being delivered through cognitive behavioural therapy and put them into practice”.
“The main message to bring across is that environmental sensitivity substantially affects clinical work and that individual differences in sensitivity have an impact on all areas of life such as parenting, the school environment, and in adulthood, the work environment. It is important to find the right environmental conditions within which the sensitive child can thrive. Some may do well even in difficult conditions if they have developed certain coping strategies. Importantly, sensitive children are doing disproportionally well in a supportive environment which means that sensitivity is an advantage in a positive context”.
Project with Syrian refugee children in Lebanon
A large and fascinating project Michael Pluess is involved with at present is looking at Syrian child refugees in Lebanon. “We have some preliminary data on sensitivity levels in response to war. In fact, we have obtained clinical data of 1,600 children, and several of these have been diagnosed with mental health conditions. In addition, we have genetic data on all included children. We currently have repeated measures of the sensitivity scale from both children and their primary caregiver. This allows us to investigate the effects of early adversities for individuals who score high or low on the sensitivity scale. It is a challenging project, but it would be very interesting to keep following these children, if we can obtain further funding.”
Do genes play a part in an individual’s sensitivity?
“Yes, ours and others’ research suggest that this is the case. According to our research, heritable factors account for about 47% of the variance between people. However, sensitivity is a common trait and most likely the result of many individual gene variants with small effects rather than a few genes. We have been trying to create polygenic scores that are based on thousands of these gene variants. But in order to achieve a reliable and robust score, we need very large samples with hundreds of thousands of people. Unfortunately, these data numbers are just not available for this trait yet”.
Can sensitivity be measured in terms of brain structures?
“Several brain regions have been identified by colleagues. In the research I have been involved in, we focused mainly on the amygdala which has originally been considered as the alarm system in the brain, a threat detection and response unit. Importantly, several of the gene variants that have been associated with sensitivity to both negative and positive experiences have also been associated with amygdala reactivity. And meta-analyses have revealed that the amygdala is responding to both negative and positive stimuli in fMRI research. In fact, in a collaborative study with professor Essi Viding
at UCL in London, we looked at the volume of the amygdala in children, we found that children with a larger amygdala were more responsive to positive aspects of the environment. These findings suggest that the amygdala may be implicated in environmental sensitivity to both negative and positive responses rather than only threat”.
Low or high sensitivity, are there advantages for either?
“There are pros and cons for both. If you’re low in sensitivity then you may end up being more protected from negative experiences, more robust, less easily stressed, basically all good things. But the negative thing is that you may also get less out of the nice things in life, maybe less out of art, social contact, may not feel things as others do. If you are very sensitive then the good thing is that if you experience positive things you will get a lot of pleasure out of it, you’ll be responsive, easily touched by nice things, you get a lot out of good relationships and understand others really well, but the downside is that you are more easily stressed, overwhelmed, and negatively affected by negative experiences. In the end, it is about the interplay between an individual’s level of sensitivity and the quality of their environment. One level of sensitivity is not better than the other. If one type of sensitivity was bad for development then over time the underlying genes would have dropped out of the gene pool, but that does not seem the case, because both high and low sensitive types have pros and cons and are therefore important for society”.
“Most of the current research is focused on the highly sensitive individuals who make up 20-30% of the population because they are more at risk of depression etc. However, around the same proportion of individuals will score low on sensitivity. Those are the ones that are not responding to psychological intervention, or social support, they appear resistant to certain treatments. We need to focus more of our research on low sensitive children because they are the ones that don’t benefit from school as much or respond to parents as well as others”.
Developmental trajectories of sensitivity
“Sensitivity also plays a role in resilience. The definition of resilience that I use is to do well despite adversity. What we found in our study
, is that sensitive individuals that have a good upbringing may develop resilience overtime. Our hypothesised explanation is that a sensitive individual in an early supported environment may acquire coping skills that then allow them to cope effectively with adversity experiences later in life. This is what I would call acquired resilience. Hence, a sensitive child is not necessarily developing into a vulnerable individual. In a very supportive environment, a sensitive child will be able to benefit disproportionately from the support and may then develop resilience which makes her comparable or even more resilient than less sensitive individuals. Therefore, we can’t just look at sensitivity at one time point and think it’ll stay the same throughout life. We need to consider the development across life because there’s a lot that can happen to an individual. But that is something that we haven’t really looked at yet. We haven’t got the longitudinal data of sensitive children, yet”.
Michael Pluess will present as a keynote speaker, his talk is titled "Individual differences in environmental sensitivity - risk and resilience, brain function and their implications for treatment".