Green neighbourhoods and their children: does it make a difference?

Eirini Flouri.

It is widely agreed that neighbourhood greenspace provides adults with emotional, physical and social benefits, especially in urban areas where most people live. Local greenery is thought to promote psychological relaxation and stress alleviation, greater opportunity for physical activity and social interaction and is related to lower levels of air pollutants, noise and excess heat.

However, there has been relatively little research into the role of neighbourhood greenspace for children. I have been carrying out some of this research in the UK since 2012 and, like others elsewhere, I am still to find robust evidence of unique benefits for the inner lives of children in the general population. Does the link exist or not?

I think it does, but the effects are more nuanced than people think. My research has found that greenspace can affect children’s spatial working memory (SWM) and risk-taking behaviour, as I will explain shortly. But potential impacts of greenspace are unlikely to emerge from a broad brush research approach.

Take, for example, the research exploring the role of greenspace in child mental health, a huge focus of scientific and public interest since the start of the pandemic. Most of this research is epidemiological in nature. As such, it uses broad measures, of both mental health and of greenspace. It then attempts (and usually fails) to establish associations between the two.

There have been some exceptions but the general pattern seems to be that local greenspace does not affect the mental health of the general child population when family characteristics are factored in. In my own research, for example, children in greener neighbourhoods did not have less aggression, greater self-regulation, greater self-esteem, happiness or positive mood, less negative mood or antisocial behaviour, or fewer emotional and behavioural problems.

It seems there is no link. Or are we using the wrong tools to look for one? Or even seeking the wrong outcomes? While the epidemiological studies don’t find emotional or social benefits of greenspace for children, they do find cognitive ones. 

Greenspace is associated with ‘cool’ cognition in children
In 2019 I published one such epidemiological study using data from the Millennium Cohort Study, a large cohort of children born in the UK in 2000-2002. That study showed that neighbourhoods with more greenspace in urban England have children with better spatial working memory (SWM) at the end of primary school. The positive link between greenspace and SWM remained even after accounting for family poverty, parental education, sports participation and neighbourhood deprivation. The size of the greenspace effect was quite small: an increase in one decile across the distribution of neighbourhoods by greenspace was associated with a decrease in roughly three-fourths of an SWM error. Importantly, however, neighbourhood greenspace was related to children’s SWM similarly in deprived and non-deprived neighbourhoods, and similarly in children with different neighbourhood histories.

I had expected a link between greenspace and SWM for two reasons. First, children in areas with more greenspace are more likely to explore their outdoor environment. This is linked to wayfinding, which is strongly related to SWM. Second, green spaces – such as parks and gardens – engage bottom-up (i.e., stimulus-driven) attention. At the same time, in such contexts the requirements to engage top-down (i.e., goal-oriented) attention are minimized. This in turn allows top-down attention abilities to be restored and replenished, leading to better performance on tasks, such as navigation, that depend on them. How is this all related to mental health? Visual and spatial awareness and the ability to process spatial information are related to mathematics performance and academic achievement in general, which is linked to mental health. Impaired SWM is in fact prevalent in neuropsychiatric developmental disorders such as autism and ADHD and is a marker for risk of psychosis.

But it affects ‘hot’ cognition too

My current research is exploring the role of greenspace in the Millennium cohort’s ‘hot’ cognition (including reward-processing and risk-taking), as measured with the Cambridge Gambling Task. Like SMW, risk-taking and reward-seeking are strongly related to mental health. I found that children in the least green areas showed greater risk-taking (Flouri et al., forthcoming). This association was significant even after accounting for neighbourhood and family socio-economic disadvantage and important individual characteristics including IQ, pubertal status and mental health. Importantly, it was nonlinear; the relative absence of contextual greenery was associated with increased risk-taking but its increased quantity was not associated with reduced risk-taking.

Hopton Almshouses Southwark

These results suggest that limited availability in urban areas of natural or semi-natural spaces, such as parks, woodlands and allotments is related to an important component of decision-making, the process of choice under risk, that is the process of making choices taking into account both their consequences and their associated probabilities. However, limited availability of local greenspace was not significantly associated with other aspects of reward and punishment sensitivity, including risk adjustment, deliberation time or delay aversion. It was uniquely predictive of risk-taking or fast decision-strategies in children, i.e., the tendency to seek quick rewarding stimuli and more risk-taking behaviours. I subsequently explored whether the link between greenspace deprivation and fast decision-strategies in children was robust to adjustments for the indoor environment and ‘objective’ third-party assessments of the home and the neighbourhood, and it appears that it is.

What comes next
These findings are, in my view, compelling enough to suggest a role of greenspace for child cognition. Whether, in general, it is greenspace abundance that confers a benefit or greenspace deprivation that causes a detriment remains to be established. It is also not clear if any cognitive effects are uniquely important for children.

In general, the epidemiological research exploring cognitive effects related to environmental exposures should embrace more warmly both cognitive geography and neuroscience. The latter would predict, for example, that children growing up in greenspace-deprived urban neighbourhoods show less aversion to risk and more impulsive choices for two inter-related reasons. 1) Because exposure to nature lengthens time perception, and lengthening time perception decreases impulsivity. 2) Because stress – which should be more likely in the least biophilic, and therefore most greenspace-deprived, contexts – affects dopamine reward-processing brain regions, by enhancing learning about positive outcomes of choices and impairing learning about negative ones.

Pictures by Naboo Photography