Wednesday, January 05, 2011

Evolutionarily Positive in the Winter Season

Ted Dobzhansky argued famously that “Nothing in Biology makes sense except in the light of evolution.” A key aspect of Biology that Dobzhansky was alluded to is the observed diversity of life and its distribution on the earth’s surface make. This makes no obvious sense when viewed as a species by species creation by a God. But in concert with what we know of the Earth’s history species diversity make good sense, especially when viewed as the result of natural evolution using data from comparative anatomy, embryology, biogeography and modern genetics. More recently some theorists in the field of Evolutionary Psychology (EP), with admittedly less data, have extended the evolutionary view to what has been called “human nature” through an evolutionary lens. This indeed was anticipated by Darwin who wrote in his 1859 On the Origin of the Species, “In the distant future I see open fields for far more important researches. Psychology will be based on a new foundation, that of the necessary acquirement of each mental power and capacity by gradation.”

Evolutionary Psychology

It does seem reasonable to believe that our understanding of the human mind would be aided greatly by knowing the uses for which it was shaped by the evolutionary process of adaptation and natural selection (as G. C Williams argued in his 1966 Adaptation and Natural Selection) and this may provide a unifying approach for understanding humans. The new discipline for study human nature this way is called Evolutionary Psychology (EP). EP a synthesis of modern evolutionary theory, studies of behavior inspired by evolutionary theory, and cognitive psychology. The result is still a young science with many debates, but some interesting perspectives on emotions, learning strategies, depression etc. Critics wonder if it is valid science because many hypotheses are hard to test. Some have called EP theories “just so stories” as a derogatory way of describing favorite alternative hypotheses cooked up as after the fact explanations for just about any human trait. The problem is that some hypotheses either are hard to test or at lack definitive empirical support when proposed. But some see EPs value with only modest existing data in tying together previously unexplained or unrelated phenomena and suggesting future tests. A good example is the grand theory that what we call clinical depression is an adaptation (see Randolph M. Nesse, article on Depression in Arch Gen Psychiatry. 2000;57:14-20.) Earlier explanations for depression (aka low mood) function in that it communicates a need for help, or signals yielding in a hierarchy conflict. Neese suggested that a more comprehensive, evolutionary explanation is possible. This requires cognitive analysis of how the characteristics of depression increase an organism's ability to cope with the adaptive challenges characteristic of:

“unpropitious situations in which effort to pursue a major goal will likely result in danger, loss, bodily damage, or wasted effort.”

In these types of situations our ancestors face, pessimism and lack of motivation may have provided a fitness advantage!

Testable Hypotheses

This grand hypothesis is perhaps currently untestable, but the idea is plausible that in early human existence inhibiting “certain actions, especially futile or dangerous challenges to dominant figures, actions in the absence of a crucial resource or a viable plan, efforts that would damage the body, and actions that would disrupt a currently unsatisfactory major life enterprise when it might recover or the alternative is likely to be even worse. “ But EP provides plausible ideas for some phenomena such as pregnancy food sicknesses. The idea is that this is a byproduct of a protective role of prenatal hormones. Thus, the theory predicts different patterns of food aversions because this is an adaptation that developed to protect a human fetus from “pathogens and plant toxins in food at the point in embryogenesis when the fetus is most vulnerable. Is it testable? There is indeed considerable studied evidence in support of this theory, including:

• Morning sickness is very common among pregnant women, which argues in favor of it being a functional adaptation and against the idea that it is a pathology

• Fetal vulnerability to toxins peaks during the first trimester, which is also the time of peak susceptibility to morning sickness.

• There is a good correlation between toxin concentrations in foods, and the tastes and odors that cause revulsion.

One of the important, but controversial areas for EP as we’ve seen, is understanding human emotions – sadness, happiness, depression. Some time ago Secular Perspectives explored the topic of “Who is Happy and Why?” This generated some discussion but did not include an evolutionary perspective for happiness. Perhaps in mid-winter with its seasonal affectations, depressions and winter blues it is time to touch on happiness and its seeming inverse depression again. For a scientific-humanist and evolutionary point of view seems like a natural way to view some of this. Indeed comprehensive evolutionary explanation of moods, happiness and depression may emerge from attempts to identify how the characteristics of each increases our own (as it had for our ancestors) ability to cope with adaptive challenges. For now we have hints and ideas of this and factors that affect our moods which have an evolutionary aspect to it.

Walk in the Wild

One aspect of our evolutionary legacy appears to be particularly relevant - a consequence of the mismatch between the present way of living and the environment of our evolutionary adaptation in our original environment. A simple example would be our physical-environment. On sunny days we can enjoy that 30-minute walk in the open air which was natural for our ancestors. We know that depriving humans or other social species of species-specific social contact and emotional support is detrimental to health and happiness, so walking with others makes it doubly nice, This makes us happy in winter and makes sense in terms of earlier human environments. And it seems to have more impact on health than people believed earlier. It is in part the sun and companionship if out as a group, but research by Britain National trust has also shown that other aspects of the natural world our species evolved in can affect us. Listening to just five minutes of birdsong a day, for example, can have a positive impact on happiness during the long winter months.

Flowers and Scents Enhance Mood

While the science of EP has applied itself to some very basic hypothesis various common experiences also make sense as EP hypotheses, and are only beginning to be tested. Thus it is folk wisdom that flowers make people happy and in cultures around the world in historical records, flowers have emotional value among peoples. But a 2005 study published in Evolutionary Psychology ( supports that with data. In this study, people were given flowers and their reactions were tested using a measurable indicator of happiness called the Duchenne smile. Women who were given flowers responded with the Duchenne smile and reported elevated moods three days later (The field of EP uses expressions in the belief that most of them are hardwired-in from birth. This means they show up across all human cultures. See Both men and women demonstrated a smiley increase in positive social behavior after receiving a flower in an elevator. For elderly people their moods brightened, but their ability to remember increased. Noting that “there is little existing theory in any discipline that explains these findings” the authors propose that floral attraction emerged as a evolutionary strategy for wild flowers - “cultivated flowers are rewarding because they have evolved to rapidly induce positive emotion in humans, just as other plants have evolved to induce varying behavioral responses in a wide variety of species leading to the dispersal or propagation of the plants.”
Similar positive effects are reported by Dr. Alan Hirsch, founder and neurological director of the Smell and Taste Treatment and Research Foundation, in several studies of the effect of scent on mood and behavior. As he says, "There is no question that certain scents have the power to inspire moods."

These are not new to many of us, but understanding such things in an evolutionary frame brings it down to earth and critically interesting for secular humanists.

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