The prairie vole has attracted some attention recently because of research into love and voles. Researchers such as Larry Young have found that the prairie vole is one of the few socially monogamous mammals—that is, a mammal that pair bonds for extended periods of time (even for life). Interestingly, this pair bonding does not occur naturally in other varieties of voles—they behave like typical mammals and do not engage in this sort of pair bonding.
Larry Young was rather curious about this feature of prairie voles and researched it. He found that the brains of the voles are such that the pleasure reward of sexual activity becomes linked to a specific partner. The specific mechanism involves oxytocin and vasopressin, but the important thing is that the voles become, in effect, addicted to each other in much the same manner that a smoker becomes addicted to cigarettes and associates pleasure with the trappings of smoking. To confirm this, Young genetically modified meadow voles to be like prairie voles. The results supported the idea that the bonding is due to the chemistry: the normally non-bonding meadow voles engaged in bonding behavior.
Humans, unlike most other mammals, also engage in pair bonding (at least sometimes). While humans are different from voles, the mechanism is presumably similar. That is, we are literally addicted to love.
Young also found that prairie voles suffer from what humans would call heart ache: when a prairie voles loses its partner, it becomes depressed. Young tested this by dropping voles into beakers of water to determine the degree of struggle offered by the voles. He found that prairie voles who had just lost a partner struggled to a lesser degree than those who were not so bereft. The depressed voles, not surprisingly, showed a chemical difference from the non-depressed voles. When a depressed vole was “treated” for this depression, the vole struggled as strongly as the non-bereft vole.
This also presumably holds for humans as well. While it is well know that humans typically become saddened by the loss of a partner (either by death or a breakup), this research also presumably suggests that human depression of this sort has a chemical basis and that it could be “cured” by suitable treatment. This is, of course, what is often attempted with therapy and medication.
While the mechanical model of love (and the mind in general) might seem like something new, the idea of materialism (that everything is physical—as opposed to some things being non-physical in nature) is an old one that dates back to Thales. The idea that human beings are mechanical systems goes back to Descartes: he regarded the human body as a purely mechanical system, albeit one controlled by a non-material mind. Thomas Hobbes accepted Descartes view that the body is a machine, but rejected Descartes’ dualism. Influenced by the physics of his day, Hobbes held that the human being is a deterministic machine, just like all other machines and living creatures.
Perhaps the most explicit early development of the idea that humans are machines occurred in Julien de La Mettrie’s Man a Machine. While La Mettrie is not as famous as Hobbes or Descartes, many of his views are duplicated today by modern scientists. La Mettrie held that humans and animals are essentially the same, although humans are more complex than most animals. He also held that human beings are material, deterministic, mechanist systems. That is, humans are essentially biological machines. Given these views, the idea that human love and vole love are essentially the same would be accepted by La Mettrie and would, in fact, be exactly what his theory would predict.
Interestingly enough, contemporary science is continuing the project started by philosophers like Thales, Hobbes and La Mettrie. The main difference is that contemporary scientists have much better equipment to work with and can, unlike La Mettrie and Hobbes, examine the chemical and genes that are supposed to determine human behavior. Without perhaps realizing it, scientists are apparently proving the theories of long dead philosophers.
The chemical theory of love does have some rather interesting philosophical implications and some of these will be considered in upcoming essays.