One of the most compelling arguments against aging being a process compounded by social conditioning is that all living beings age. If we assume animals age, and that they do not have the capacity to be ‘conditioned’ by social conventions, then surely that is sufficient proof that aging is purely biological, and therefore unavoidable.
Aging in life forms other than humans does vary enormously however, and differs sometimes quite spectacularly from the way we grow older and die.
In the case of plants, for example, if a graft is taken from one, grown into a new plant and if that graft outlives the first plant, is it a new plant or is the same one? Grafting can in theory go on forever – it is widely used in agriculture, and species such as bananas and tulips are examples of how it can be continued for thousands of years. Aging in plants is therefore difficult to define. Many plants do of course decline over time – fruit trees become less productive and hormones produced by the roots or the growing tips are thought to influence this process. However, pruning can lead to a sort of rejuvenation. In rejuvenation pruning, the shrub is pruned by cutting off all old branches at or near ground level. Healthy shrubs will respond by sending up multiple new shoots. Indeed, some plants show no evidence of senescence; the bristlecone pine lives on high rocky ground and has been estimated to live for more than 4000 years with no decline in reproductive output.
Simple animals that live around hydrocarbon seeps also show unusual longevity. One of the species with the longest longevity (250 years) is an invertebrate tubeworm called Lamellibrachia. Other invertebrates displaying what is known as negligible senescence are the red sea urchin and the bivalve mollusc ocean quahog. Some snakes might also escape senescence; many snake species actually lay more eggs as they increase in size with age. Even though these animals will eventually die, they do so without actually having aged.
When we consider mammals however, no species has been found that does not display aging. The longest-lived mammal is the bowhead whale (over 200 years), but the pathophysiology of aging is remarkably similar in mammals, which has implications for our understanding of genetic mechanisms of aging. Size seems to be irrelevant, since a chipmunk can live 5 times as long as a rat. We are smaller than grizzly bears, but live twice as long. Brain size may therefore be a factor.
Animals certainly display aspects of consciousness. The weight of evidence indicates that all mammals and birds and many other creatures including octopuses possess the neurological substrates that generate consciousness. Animals are also subject to social conditioning. Social interaction is often crucial to the animals, and who is to say whether they too (if they are not killed by a predator) learn to age and die as a result of learned behaviour in the group, or by being part of the collective consciousness of that species?
However, there is one obvious difference between animals and humans. We are self-aware and have the capacity to control our physiology and our lifestyle, and of course our thoughts and attitudes. Some higher animals – primates, dolphins – are capable of recognising themselves in a mirror, but this is a long way off creating great works of art and feats of engineering. It is also a long way away from an understanding of consciousness itself. The moment in Edgar Rice Burroughs’ Tarzan of the Apes when Kerchak the envious ape king attacks Tarzan and Tarzan overpowers him has taken a place in modern mythology as an example of man’s superiority over animals. The story is timeless, and a new version of Tarzan directed by David Yates is currently in the making.
Humans display ‘self-consciousness’, also known as meta-self awareness, which involves imagining how others might judge us in a public situation or being capable of dissociating by immersing ourselves in a book or film. A theologian might put it rather differently : although animals have souls (anima is Latin for soul), our souls are rational and theirs are not. Animals and plants have no moral sense – they are incapable of ‘sin’. They cannot analyse feelings and are incapable of abstract thought.
It is this capacity for abstract thought that is at the root of the idea that humans can take control over their bodies. No animal is capable of intentionally displaying the power of mind over matter but by slowing down their bodily processes Yogis can survive a live burial for far longer than the average person. Tibetan monks have dried sheets by generating body heat in a room at only 4°C. There is also a famous experiment done by Harvard psychologist Ellen Langer, involving overweight chamber maids who were on their feet all day and ought to have been thin. Langer discovered that 67% of the maids felt they didn’t do any type of exercise. When Langer explained to half of the group that they exceeded recommended activity levels, these women not only lost weight and regained their waistline but experienced a drop in blood pressure. The other half saw no change. Langer concluded the results were due to a change in perception.
We are part of the collective consciousness of the human species, but we have the power to step outside it. Bucking the trend, introducing new paradigms and revolutionising old patterns of thought is what our species is about. If we could convince animals they had control over their health and the way they age, then we would witness a change in animal senescence. But ideas cannot be communicated to animals and hence no animal is capable of this. Thus they remain subject to the natural laws of this earth.
We humans are also subject to the natural laws of the earth. However, evidence is growing that we have the power to transcend them.