Investigating the factors that cause stress in young children and how this affects their concentration

I am a research scientist based at the University of East London, who receives funding from mainly government-funded research sources. The main focus of my research is on investigating the factors that cause stress in young children, and how this affects their concentration. When I was approached by the Assistant Headteacher of a local school, I jumped at the opportunity for us to do some research together. The school is an inner-city school in a highly ethnically diverse and socio-economically challenged area, and the kinds of children who attend are exactly the kinds of children I am interested in understanding better. The research followed ethical guidelines with informed consent.

Stress systems and their impact on children

One of the main focuses of my research is on trying to understand the mechanisms that lead to poorer mental health outcomes in people from the lowest socio-economic brackets. We know that children who grow up in particularly poor families are four times more likely to develop a serious mental health problem over the course of their lifetime. (Businelle et al., 2013). They are at increased risk of developing all different types of mental health problems – there is no one problem in particular that is more affected (Conway et al., 2018). Recently, research has suggested that one mechanism that might cause this is early-life stress (Businelle et al., 2013). The idea is that increased early-life stress might cause our physiological stress systems to be affected – and this, in turn, might impair our ability to regulate and control our behaviours in a range of settings.

Roughly put, our physiological stress systems consist of two branches – the sympathetic, or ‘fight or flight’ system, and the parasympathetic, or ‘rest and digest’ system. The ‘fight or flight’ system does what it says it does – it kicks in when our brain tells our body that we are in danger, and it involves a set of changes to prepare our body for fight, or flight: our heart beats faster, we start sweating, our mouth dries up (to economise on liquid), the bronchi in our lungs dilate, and our immune system shuts down (to conserve energy). The parasympathetic ‘rest or digest’ system is essentially the opposite set of mechanisms, that kicks in when brain tells our body that we are safe and can concentrate on long-term aims, such as resting and digesting our food.

Nowadays, we very rarely actually have to run for our lives, or chase after something before we eat it – but our fight or flight system, which has evolved over hundreds of thousands of years, remains. This is why what many people recognise as signs of psychological danger, such as a job interview, are accompanied by symptoms such as a dry mouth, a pounding heart, and excess sweating. This is our body responding to psychological danger as if it’s an actual physical threat, that we’ll have to run away from. And it’s also why students tend to get things like cold sores and colds during exam season – because the immune system shuts down with stress.

We know that children have the same basic stress systems, too. And we know that early life experiences can affect children’s stress systems in a variety of ways (Beauchaine & Thayer, 2015; Lupien et al., 2009). For example, they can lead to some children getting ‘stuck’ in ‘fight-or-flight’ mode. Or they can lead to some children becoming hyper-reactive – and showing a tendency to shift suddenly from ‘rest and digest’ to ‘fight or flight’ on the smallest provocation. And a third, and related, problem, can be that some children can be impaired at regaining control after something has gone wrong.

I’m interested in exploring how these systems can go wrong in children from particularly tough home environments. But I’m also interested in a couple of other things, too. First, I’m interested in how the early environment that we grow up in – whether it’s urban, and cramped and noisy, or rural, and more spacious and spread out – can affect our stress systems. There’s very little research out there into how our early living environment affects us – how city children are different from country children – but I think it’s a really important area to consider.

Secondly, I’m interested in how sensitivity isn’t always necessarily a bad thing. Indeed, there is a lot of research suggesting that sensitivity can be a double-edged sword (Ellis & Boyce, 2008). Children who are naturally sensitive benefit the most from a good, nurturing or interesting environment – because they are more sensitive, and better able to register and record enriching new experiences. But those same, more sensitive children are also those most affected by a negative, unsupportive environment. Whereas children who are naturally less sensitive, are less affected by their environment either way. Colloquially, the sensitive children are often described as ‘orchid’ children – an orchid being a flower which is very particular about where it grows. Whereas less sensitive children are often described as ‘dandelion’ children – because dandelions will grow anywhere.

A classroom-based research project on stress systems

This piece of collaborative research immediately appealed to me due to the unique opportunities it offered. Most of the research that we researchers conduct involves bringing large numbers of children into the lab, for testing using a small set of experimental tasks. Because so many children are involved, you don’t get to know them very well – indeed, in research you make a point of anonymising the results, and only looking at patterns across the group as a whole.

The perspective of an Assistant Headteacher was very different; she had access to a much smaller group of children than is traditionally used in a research study, and knew each of these children individually. She concentrated on looking at the physiological stress systems in a group of 10 children in her class across four testing sessions. Measuring physiological reactions was fairly straightforward; we purchased a number of commercially available heart-rate monitors, which are low-cost, as many people use them in sports training. The Assistant Headteacher conducting the study put the heart rate monitor on those children participating at the beginning of each school day, and then took it off at the end. She made notes during the day of any particular events that occured, and then we looked at the data together afterwards. The aim was to prepare a series of Case Studies, looking in detail at individual children, and informed both by prior knowledge of what they were like as people, and by the data that we had collected, and the previous research findings into how our stress systems work.

Primary Assistant Headteacher

Sam’s areas of interest felt very relevant to me as a teacher because I had recently been reading a lot about children’s stress response systems and how these relate to behaviour and wellbeing. This had first been brought to my attention when introduced to Polyvagal theory (Porges, 2007) on a course about how best to support children with emotional and behavioural difficulties. Polyvagal theory asserts that when children’s fight/flight system is activated, they are unable to access higher-order thinking skills, creativity or socially engage with others effectively. Therefore, it is imperative to support children in learning how to regulate their stress responses, and to ensure that they feel in a ‘safe state’ at school if we want them to learn and interact successfully.

I was fascinated by the link between children’s bodily and emotional states, and surprised that I was never taught anything about this in teacher training. The more I read on the subject, the more I felt that to support children’s emotional wellbeing effectively, we need to be better informed about the close ties between physical and emotional regulation. This is an area which has been researched for decades but does not seem to broken into mainstream knowledge for educators.

Abnormally low resting heart rate has been linked to a wide range of psychological problems including anxiety, phobias, depression and hostility (Beauchaine & Thayer, 2015), whilst indicators of higher levels of parasympathetic activity have been correlated with a range of favourable behavioural outcomes including responding sensitively to others (Fabes, Eisenberg, & Eisenbud, 1993) using effective coping strategies, social wellbeing (Geisler et al., 2013) and showing empathy (Diamond, Fagundes & Butterworth, 2011).

However, the majority of this research has been conducted in the laboratory under experimental conditions. This means that results from such studies can be difficult to replicate in school settings and rarely have clear implications for daily teaching practice. Therefore, I was excited to have the chance to conduct my own study which would be more naturalistic and reflect how children react to everyday events in their school setting rather than artificial situations in a lab. To explore this, I combined detailed heart rate data about each child, along with behavioural and emotional wellbeing questionnaires and observations to create an individual profile for each participant. Creating these case studies allowed me an insight into each child’s behaviour, how it related to their physical state, and how I might best be able to support them as a teacher.

Research findings – What did the case studies tell us about individual children?

One child, who I will refer to as child 1, was identified by teachers as the least disruptive participant in the sample. He had the 3rd best concentration out of 10 participants and was also highly prosocial (ranked 2nd). Within lessons he was observed to be a well behaved and engaged participant; currently working above the national expectations for his age in all subject areas. His heart rate profile matched this description of his behaviour: he did not have a high mean HR, suggesting that he was not anxious, stressed or over-excited during classroom activities. He also showed a large increase in HR during playtime but this high HR dropped rapidly at the end of playtime suggesting that good vagal control allows effective calming when re-entering the classroom. In keeping with this assertion, child 1’s HR variability data ranked him as the most parasympathetic participant. This means that he spends more time in ‘rest and digest’ mode than other children in the sample.

However, it is more complicated than just being more parasympathetic. Child 1’s heart rate data also suggested that he is naturally more engaged with (or stimulated by) the outside world than some other children. He had one of the highest standard deviations in mean heart rate across the 4 days of data collection, suggesting that he is physiologically responsive to changes in activity and routine across different days. However, he is able to regulate this level of engagement. This ability to respond adaptively to his environment, suggests that child 1 has autonomic flexibility and it may be this flexibility which has provided the right physiological conditions for him to achieve well academically and socially.
Although he could be considered an ‘orchid child’ because of his sensitivity to the environment around him, this has not affected him negatively. Child 1 has supportive parents who are highly engaged with his education. He also has no known challenges in his home life. His sensitivity may therefore have enabled him to reap the benefits of a favourable home environment. However, if life were to become more stressful, child 1 may be more affected than a dandelion child would be.

Being equipped with this information may help to pre-emptively maintain child 1’s academic success and general wellbeing. For example, each September children move into a new classroom with a new teacher and a new cohort of peers in their class. Child 1 may be more sensitive to these changes than other children and so may benefit from additional transition measures such as meeting his new teacher and classmates before the summer break or having an adult who is already familiar to him working within the classroom. His relationship with the teacher may be particularly influential and worthwhile investing time in developing, as research has suggested that child-teacher relationships are substantially associated with mental health outcomes, particularly for more reactive children (Essex et al., 2011).

In contrast, child 2 was identified by teachers as the participant who was the 2nd most disruptive in the sample, and the least prosocial. Child 2 often presented as expressionless and disengaged. In previous years, concerns were raised that child 2 was sometimes aggressive and showed a lack of emotion. In nursery, he did not meet developmental milestones related to making relationships and managing feelings. These factors would suggest that child 2 is low in parasympathetic activity and therefore may have a high mean resting heart rate.

In keeping with these predictions, child 2’s mean classroom based HR was the highest in the sample, this was consistent across data collection days. Child 2’s HR variability also ranked him as one of the least parasympathetic participants meaning that he spends less time in ‘rest and digest’ mode and more time in ‘fight or flight’. This is not surprising given his low score for pro-sociability and reported lack of emotional expression, lending support to Polyvagal theory’s assertion that the vagus (a key nerve in the parasympathetic system) regulates both the heart and the facial muscles related to our social engagement system (Porges, 2007).

Low parasympathetic activity combined with a lack of prosocial behaviour suggests that child 2 may be feeling both physiologically and emotionally dysregulated. Therefore, possible interventions which may be effective include calming relaxation exercises such as paced breathing and specific teaching of emotional vocabulary and the bodily sensations which accompany different emotions. Research supports the efficacy of interventions such as these (McCraty and Childre, 2010) and suggests that they can change stress response systems over time. Without first regulating himself physiologically, it is unlikely that child 2 will be able to engage in many of the requirements of the primary classroom, for example, working effectively with a peer or group.

Implications for teaching

Evidence that physiological and behavioural regulation can be improved and that stress response systems are changeable has important implications for teachers. Long term interventions targeting ‘high risk’ children with vulnerability to stress and hypersensitivity to the environment have been found to result in greater wellbeing and reduced instances of violent crime and drug offences in later life, as well as reducing the prevalence of psychiatric diagnoses such as Conduct Disorder and Oppositional Defiant Disorder (Conduct Problems Prevention Research Group, 2011).

When adults talk about stress they normally think of it as something they would wish away if they could. But my conceptualisation of stress within these children has been more focused on reactivity. Our stress system is a mechanism that helps us accommodate change. What is challenging for children – and more difficult for some individuals than for others – is to find the optimal level of reactivity. Some children have a tendency to overreact to all forms of change or stimulation, just as other children have a tendency to under-react. Studying children’s’ heart rate was a way of observing and reflecting on this reactivity and how it affects children in their lives at school.

Looking back at my own behaviour management strategies, I have definitely asked a child in the past to reflect on what they have done wrong and think logically about the situation when they were still in fight/flight mode, and therefore unable to access the higher order thinking skills I was asking of them. Similarly, when I read about overactive stress response systems that lead to hyper-vigilance, I am able to relate this to those children I often see wandering the corridors, unable to settle on a task for long, who are quick to become defensive. Understanding the physiological basis of these behaviours helps me to support these children and co-regulate them into a state where they are better able to access their education.
Berntson et al. (1997, p.641) assert that ‘Psychology and physiology are interwoven inextricably.

Psychological processes are also physiological processes, they cannot be understood fully without detailed consideration of the structural and functional aspects of… the nervous systems’. Therefore, we mustn’t ignore the important part that physiology plays in how children learn, behave and relate to others in school.
10% of children aged 5-16 in England currently suffer from a clinically significant mental health illness, whilst 1 in 4 children are thought to show some signs of ill mental health (Young Minds, 2017). The more we are able to know and understand pupils on many different dimensions, the more likely it is that we can identify and provide the support that they need.