Excerpted from GOOD NATURE: Why Seeing, Smelling, Hearing, and Touching Plants is Good for Our Health by Kathy Willis with permission from Pegasus Books. Copyright © 2024 by Kathy Willis.
Recently I found myself walking around the Botanic Garden in Oxford. This beautiful and historic location, right in the heart of the city, attracts over 200,000 visitors a year to its tranquil walkways and restful vistas.But it wasn’t just the elegant variety of plants, or even the impressive range of the scientific research being undertaken here, that caught my attention. It was a small child reaching out to touch the leaf of a rose, and her grandmother, instead of telling her not to touch, stroking the silky petal against her cheek.The child was intrigued and delighted.
We are often told, ‘Don’t Touch’ and ‘Keep Off The Grass’. Maybe it’s time to ditch those outdated attitudes. Maybe experiencing nature through the medium of tactile interaction with leaves, bark and petals is good for us. Maybe Grandma was right.
The urge to touch things is one we have from a very early age. Take a toddler into a shop, and they simply have to touch everything in sight. This is because we use touch to learn. But is there a deeper significance to our response to how nature feels, as well as to how it looks, sounds and smells?
A few years ago, the idea of allowing animals into hospital wards, nursing homes and children’s vaccination clinics would have been unthinkable. The risk of infection would have been regarded as too great. Times have changed. When I recently visited an old relative in a care home, the room was full of dogs being stroked by the residents. It was clear from both the senior citizens’ faces, and the dogs’ wagging tails, that there was a joint ‘love-in’ going on. The happiness and mental well-being that stroking these dogs was bringing to the residents was clear to see – and it also made it clear to me why it is increasingly common to see therapy dogs in clinical environments. The positive emotions and reduced fear and anxiety that occurs when touching and stroking these dogs are now often deemed to outweigh the risks associated with their potential biohazard.
Interestingly, these studies are also revealing that individuals who engage in more physical contact with the dogs during these interactions show lower stress levels afterwards, suggesting that it may well be this element of tactile stimulation (touch) which provides the benefits we typically associate with being around animals.
But does the same thing work with inanimate nature? Can we derive similar benefits from touching leaves, stroking the bark of trees or even the timber of the trees, plant material that is long since dead?
Many of us certainly seem to have an instinctive wish, even need, to stroke the surfaces of wooden furniture – as beautifully illustrated in a conversation I had with Barnaby Scott, a local furniture maker in Oxfordshire who founded the company Waywood:
When people see my furniture, the first thing they ask is whether they can touch it, they’re diffident, but we’re all strongly drawn to touching wood and it is reassuringly warm.
And from the conversation it was clear that it is not just his customers that feel this way:
Wood provides a warm, reassuring environment with lovely associations from the living world, which other materials don’t. When the workshop was asked to cut some plastic fence rails, we couldn’t wait to get rid of them and return to our wood – the difference for everyone was palpable.
But what actually happens to us when we touch and stroke plant material? Does it invoke some of the same physiological and psychological calming mechanisms that occur when we stroke and touch certain animals? Should we hug trees in the park with the same lack of self-consciousness with which we pet our neighbour’s cat? It has been known for a long time that gardening is associated with many positive health benefits for young and old. Horticultural therapy is now a well-recognised occupational health intervention for those with mental health conditions such as depression and memory loss, particularly older people. It has also been shown to be effective at reducing some of the chronic symptoms in patients with schizophrenia, and reducing stress levels and agitation in children with Attention Deficient Hyperactivity Disorder and autism. It is often assumed that ‘being outside’ will do the trick by providing the combined benefits of sound, sight, smell, exercise and social interaction. This is probably correct – it is a combination of them all. But what specific role does touch play in this? Can we isolate its effects from our other senses? For example, therapeutic animal petting sessions often take place indoors without the additional environmental stimuli of the smells and sounds of nature or increased exercise. Are there specific changes that are triggered in our bodies when we touch plants?
One intriguing experiment that started me on this journey of questioning whether touching plants has an impact on our physical and mental well-being was one in which participants sat in a clinical environment with their eyes closed and were asked to touch four different materials: a leaf of a living pothos plant (Epipremnum aureum, which we have met already under its alternative name, devil’s ivy); an artificial pothos leaf made from resin; a piece of soft fabric; and a metal plate. While doing so they had their brain scanned using infrared spectroscopy in order to detect changes in cerebral blood flow and therefore central nervous system activity. Clear results emerged: touching the living leaf of the pothos plant resulted in a significant calming response compared to touching the other materials. This was a simple experiment with a small number or participants – just fourteen. But, for me, it raised other questions – not least, how common are these sorts of responses when we touch and stroke plant material such as the different types of wood, or the leaves on a living plant? Also, which parts of our bodies should be doing the touching; is it just touching with our hands, or do we get a similar response when, for example, we walk barefoot on grass or wooden floors? These experiences are often part of our daily lives; are they actually doing us good? Should we actively seek them out?
We each have millions of receptors which respond to various touch stimuli distributed throughout our skin. However, certain parts of our bodies – our face and hands, for example – have a much higher density of these receptors. This explains why these areas are much more receptive to external physical stimuli, including touch. There are also several different kinds of receptors in our skin, stimulated by mechanical touch (stroking, stretching, vibration), temperature (thermoreceptors) and chemicals (chemoreceptors). Our skin, muscle, joints and most of our internal organs also contain pain receptors (nociceptors) that are activated by actions that potentially damage tissue. When we touch something, these receptors are activated and generate signals which travel along sensory nerves to neurons in the spinal cord and to the thalamus region in the brain. The neurons in the thalamus region then relay signals to other parts of the brain that trigger a variety of different responses including, for example, movement of our limbs, change in our heart rate, respiration rate, attention, focus and awareness. This is the practical, physical response to the stimuli provided by the biology of touch.
Win the Holidays with PopSci’s Gift Guides
