Is Variety the Spice of Life? An Experimental Investigation into the Effects of Species Richness on Self-Reported Mental Well-Being

Losses in biodiversity and trends toward urbanisation have reduced people’s contact with biodiverse nature, yet the consequences for mental well-being are not well understood. Here, we demonstrate that greater plant and animal species richness in isolation causes an improvement in mental well-being. To do so, the present research experimentally manipulated species richness and assessed widely-used indicators of mental well-being. Participants viewed short videos of either high or low tree (Study 1) or bird (Study 2) species richness and reported on positive (i.e., vitality, positive affect) and negative (i.e., anxiety) indicators of mental well-being. Building on Study 1, Study 2 included an urban environment as a reference treatment and explored the role of giving participants information on the presented environment. We find that, in line with expectations, watching videos containing greater species richness consistently leads to higher mental well-being. We discuss findings in light of the importance of connecting people to biodiverse environments.

生物多样性流失与城市化进程加剧，削弱了人类接触具有生物多样性的自然环境的机会，但其对精神健康福祉（mental well-being）的影响尚未得到充分阐释。本研究证实，在控制其他变量不变的前提下，提升动植物物种丰富度即可改善精神健康福祉。为此，本研究通过实验手段操控物种丰富度，并采用学界广泛使用的精神健康福祉评估指标开展测评。参与者观看了分别包含高、低树木物种丰富度（研究1）或鸟类物种丰富度（研究2）的短视频，并对自身精神健康福祉的正向指标（即活力、积极情绪）与负向指标（即焦虑程度）进行自评。在研究1的基础上，研究2增设了城市环境作为对照处理组，并探究了向参与者提供所展示环境相关信息的作用。研究结果与预期一致：观看物种更丰富的短视频可持续提升参与者的精神健康福祉。最后，我们结合推动人类接触生物多样环境的重要意义，对本研究发现展开了讨论。