14 Apr 2013
Maladaptations of the Pleistocene
mal·a·dap·tive – Not providing adequate or appropriate adjustment to the environment or situation
The last post was about fast food as maladaptation. The preference for fat and sugar which leads to fast food is not the only maladaptation. The preference for pornography is another. In a way, fast food is indeed like pornography: it is a bit like the real thing, and seems to taste well in the beginning, but is not really satisfying in the end. And it is not good for you. Constant stress is not good for you, either, although it was once useful to be instantly ready for fight or flight responses. A recent book about maladaptation says (Jerome Wakefield, chapter 5, p. 168 [1]):
“In our own society there are features of ours likely naturally selected, such as a taste for fat and sugar, a fight-or-flight response to stressful situations, shyness about speaking to groups of strangers, and sexual desire not limited to our spouses, that cause us much trouble. In the new environment we have created for ourselves (plentiful food availability, high stress, mass communication, lots of interaction with other people’s spouses) these features, which may previously have helped us survive, cause us problems.”
Our bodies have evolved to eat, survive and reproduce in an environment where food and mates were sparse, where stress and stressful emergencies were unpredictable and rare, and where there was plenty of space and large need for movement. Now we have plenty of food, sit around the whole day in a stressful office, move around in public transport, and watch porn on the internet. It is not surprising that this behavior makes us sick. As Robert Sapolsky has shown [2], our bodies are not designed for the 21st century and the constant stress of modern life. They are more suited to life of the Pleistocene and in the open Savanna. The constant stress in noisy offices and polluted cities makes us sick and leads to stess related and cardiovascular diseases, for instance ulcers and coronary heart diseases. Zebras don’t get ulcers, as Sapolsky observed cleverly [2], because they do not sit around in smelly and noisy offices the whole day. If the stress response set ins, they simply run away and outrun the lion.
A changed environment has turned useful adaptation into maladaptations:
- Desire for Fat and Sugar (=> Fast Food related diseases)
- Stress Response, Need for movement (=> Stess related cardiovascular diseases)
- Desire for Mating (=> Sex addiction)
- Flexible sexual desire based on imprinting (=> Pornography)
We have all kinds of mental disorders in modern life as well, addictions, depressions, phobias, mental disorders etc.. They are not directly maladaptations, but often byproducts of emotions. Emotions have an evolved function, i.e. they are normally useful and adaptive, but can go “off the rails” in certain cases in wrong environments. Fear and anxiety are natural responses to life-threatening situations. In modern environments there are no longer big cats and wild cave bears. In our world traffic accidents are much more life-threatening than meeting a lion, tiger or leopard. Thus we develop traffic phobias after traffic accidents instead of being frightened of dangerous predators after meeting one [1] . Mild forms of depression for instance are natural, too. They are a useful response to disengage from useless efforts and failing enterprises [1], as we have discussed earlier depression is an adaptation to hopeless situations. But in modern environments this “disengagement” mechanism can be maladaptive, for instance if many people just can not find a job (due to bad political or economic conditions) it will make them sick.
But we are a clever species, and we will find a way to cope with it 😉
References
[1] Maladapting Minds: Philosophy, Psychiatry, and Evolutionary Theory
Pieter R. Adriaens, Andreas De Block (Editors)
Oxford University Press, 2011
[2] Why Zebras Don’t Get Ulcers: An Updated Guide to Stress, Stress Related Diseases, and Coping
Robert M. Sapolsky
W. H. Freeman, 1998
(The image of the tiger is from Wikipedia)