What we already know
Evidence on the impact of the outdoors and nature on children's physical, cognitive, social and emotional health, wellbeing and development is more established compared to nature-based Early Learning and Childcare (ELC). For, example, consistent research tells us that when children are outdoors, they engage in higher levels of physical activity which is important for reducing negative health outcomes, such as obesity, cancer, cardiovascular disease, and depression among other outcomes. Similarly, in older children and adolescents (5-18 years), non-educational nature-based settings has a positive impact across a number of outcomes. Nature appears to be particularly beneficial for physical activity and outcomes related to mental health. Less evidence exists on whether nature can enhance children's cognitive and learning outcomes, but these can be improved through increased levels of physical activity.
What this review adds
To our knowledge, this is the first systematic review to synthesise global evidence on the role of nature-based ELC on children's health, wellbeing and development. The evidence thus far, as described above, exists primarily in conceptually similar research fields (outdoors and nature more broadly) and in older children and adolescents (5-18 years). This means that we cannot be certain that the benefits older children and adolescents gain from being in nature will be similar to the benefits of nature-based ELC on younger children.
Overview of methodology
The purpose of this systematic review was to understand the extent to which nature-based ELC influences children's (2-7 years) physical, cognitive, social and emotional, and environmental outcomes.
A search for literature was conducted in 9 databases and websites to find relevant global evidence. Studies were included in this review if a) children were in ELC and had not started primary school, and b) the ELC settings provided children with exposure to nature, and c) included child-level outcomes related to health, wellbeing and development.
To provide a level of scientific trust in our studies and subsequent evidence, we conducted two assessments:
I. Assessment of the quality of the studies
II. Assessment of the certainty of the evidence
To understand the quality of eligible studies, we used the Effective Public Health Practice Project (EPHPP) tool (quantitative) and Dixon-Woods checklist (qualitative). This assessment aids in the interpretation of findings from each study. For example, if a study was rated weak then we should interpret its findings with caution.
The Grading of Recommendations Assessment, Development and Evaluation (GRADE) framework was used to assess the certainty of the evidence for a single outcome which has been reported in more than one study. This assessment provides a rating that enables us to draw conclusions about the findings reported at an outcome level. For example, if the certainty of evidence is low for a specific outcome, we need to be cautious in our interpretation of the findings and subsequently the recommendations.
To present the findings for quantitative evidence, studies with the same exposure and reported on similar outcomes were grouped and summaries provided based on whether evidence favoured nature (i.e. nature-based ELC) or favoured the comparison (traditional ELC). A narrative synthesis was conducted to report on findings grouped by outcome domains with the better-quality evidence prioritised in any conclusions drawn. For qualitative studies, a thematic analysis of reported themes was conducted, grouping them into lower and higher order themes.
Overview of the included studies:
The findings presented in this report are based on 59 unique studies (representing 65 articles). Most of the studies were published in the USA, Australia and Norway. Only 3 studies were published in the UK, of which, one study included data from Scotland. For the quality of the included studies, the majority were rated as weak. Studies were generally given a poor rating because participants were unlikely to be representative (selection bias), it was unclear whether the researchers or outcome assessors were aware of the research questions (blinding) and withdrawals and dropouts were not reported or was high (in before and after studies only). Study designs were also rated weak because most were controlled cross-sectional and cross-sectional studies. Outcomes of cross-sectional studies were assessed at a single timepoint only and so permits drawing conclusions about the causal link between nature exposures in ELC and health and wellbeing outcomes in children. Given the large number of weak studies, it is important to interpret study findings with caution because it is difficult to know for certain if any possible benefits are as a result of attending nature-based ELC and not any other influencing factor.
Findings for child-level outcomes:
The quantitative element of the review reported generally favourable findings on the role of nature-based ELC on children's physical, cognitive, social, emotional and environmental development compared with traditional ELC. The findings reported are dived into 3 categories:
i) likely positive association – positive health outcomes with most studies associated with nature-based ELC;
ii) likely negative association – negative health outcome with most studies associated with nature-based ELC; and
iii) inconsistent findings– unclear whether these studies favoured nature-based ELC or traditional ELC (i.e. not enough evidence).
The evidence suggested that there were no harms associated with attending nature-based ELC.
Based on very low and moderate evidence, playgrounds which included grassed areas, vegetation, natural elements, rocks, hills or shaded areas were positively associated with increased total physical activity, moderate-to-vigorous physical activity (MVPA) and step counts and decreased sedentary time during ELC.
Based on low and moderate evidence, compared to traditional ELC, nature-based ELC was positively associated with:
- self-regulation (ability to understand and manage behaviour)
- nature relatedness (or biophilia)
- play interactions
Based on moderate evidence, compared to traditional ELC, nature-based ELC was negatively associated with children's speed and agility.
Based on very low, low and moderate evidence, compared to traditional ELC, nature-based ELC had inconsistent findings on the following outcomes:
- object control skills
- social skills
- social and emotional development
- awareness of nature
- environmentally responsible behaviour
- behavioural problems (such as temper tantrums or hyperactivity)
- play disruption (aggressive and antisocial behaviours in play) and disconnection (withdrawn behaviour and nonparticipation in play)
Similarly, the qualitative (e.g. practitioner reported feedback) element of the review reported generally positive findings:
- Nature affords many more opportunities for children to be active, diversify their play, engage in risky play, interact with peers and teachers, increase their creativity and enable child-initiated learning compared to traditional settings.
- Nature-based ELC affords opportunities for children to be physically active, to engage in diverse types of play and interact with peers. This combination is likely to have an impact on a range of physical, cognitive, and social emotional and environmental outcomes
- Children prefer settings which integrate some nature: either a full naturalised playground or a mixed area. A small number of studies indicated that movement and risky play were similar no matter the setting type.
In summary, evidence suggested that specific natural elements: grass, hills, vegetation, or rocks had a positive association with MVPA, total physical activity and reduction in sedentary time during the ELC day, whereas trees may limit physical activity levels. Findings for motor competence were mixed: generally, balance was better in children who attended nature-based ELC, but they performed worse in a test of speed and agility compared to children from traditional ELC. Findings for object control skills and illnesses were inconsistent. For the cognitive domain, children who attended nature ELC also demonstrated better levels of self-regulation (ability to understand and manage behaviour) compared to typical ELC settings. However, findings for attention were inconsistent. For emotional outcomes, findings were inconsistent for social skills, social and emotional development, attachment, initiative and behavioural problems. For environmental outcomes, nature relatedness was higher in children who attended nature-based ELC compared to traditional ELC. However, findings were also inconsistent for awareness of nature and environmentally responsible behaviour. There was also an indication that play interaction was higher in children who attended nature ELC compared to traditional ELC. Findings for play disruption and disconnection were inconsistent.
Findings from the qualitative evidence suggests that compared to traditional settings, the natural environment affords many more opportunities for children to be physically active, play and interact with their peers. Children also prefer settings which integrate some nature either a full naturalised playground or a mixed area.
The evidence base in the present report makes it difficult to provide strong recommendations. The evidence is predominately weak and outcomes were assessed over a short period of time meaning that we could not fully understand the mechanisms by which any improvements may have occurred. However, based on the available evidence, there are three suggested recommendations:
1. Ensure that ELCs have a rich and varied environment that includes a combination of grassed areas, vegetation, natural elements, rocks, hills and/or shaded areas. These appear particularly important for encouraging physical activity, diversifying play types and enabling human interactions which are all important for childhood development.
2. Ensure that all children can access nature across all setting types: outdoor; indoor/outdoor; satellite. In studies where there was a likely association, evidence from this review suggested that both indoor/outdoor and satellite approaches provided children with high exposure to nature. Therefore, it is important to understand how much and how regularly (daily, weekly, etc) children are exposed to/engage with nature across each setting.
3. To aide future policy development in Scotland, it is important that researchers work collaboratively with practitioners and policy makers to establish what child and ELC level outcomes should be measured and how we can best collect data on these. By embedding robust evaluation practices, we can generate stronger evidence on the impact of nature-based ELC in Scotland.