evolutionary psychology — it’s all in your mind

It’s everywhere these days. Whether the topic is economics or romance, politics or sports, articles often refer to studies that explain why we do what we do from an evolutionary perspective.

Since survival of the fittest shaped our minds as well as our bodies, the research strategy is to determine how any (and every!) behavior contributed to gene propagation. According to the Center for Evolutionary Psychology (CEP), such findings prove evolution’s importance:

[C]onsideration of how humans evolved can inform various subfields of neuroscience and psychology. The very idea that humans evolved has come under legal siege in the U.S. during the last several years. It is important to continue to demonstrate that humans no less than other species show significant evidence of being the organized product of natural selection —- and in subtle, unexpected ways not easily explained by blank-slate learning or “intelligent design”. (source)

Sadly, despite so hefty a claim of importance, evolutionary psychology makes presumptions that lead to hasty conclusions, neglecting to investigate fully the reasons for our behavior.

Consider a recent study by Yale postdoc Joshua New, who used pairs of images with just one change to find that the human mind pays more attention to animals than to inanimate objects:

Recent experiments show that the visual priorities of our hunter-gatherer ancestors are embedded in the modern brain. What our eyes look at is guided by brain mechanisms that pick out some portions of a scene over others. Since keeping an eye on predators and prey was important during our evolution, Joshua New and colleagues investigated whether animals, both human and otherwise, are more likely to draw visual attention spontaneously. The researchers showed subjects pairs of photographs of natural scenes in rapid alternation, with the second photograph including a single change. As predicted, subjects were faster and more accurate detecting changes involving animals than inanimate objects. If experience were producing this attentional bias for animals, then people should also be good at detecting changes to vehicles -— they have been trained all their lives, as drivers and pedestrians, to monitor vehicles for sudden, life-or-death changes in trajectory. Yet they were much slower in detecting changes to vehicles than to more rarely experienced animal species, indicating that learning is not the source of this difference. The bias for animals, the authors conclude, is like the appendix —- present in modern humans because it was useful for our ancestors, even if useless now.

We derived the hypothesis of an animal monitoring system by considering what impact an evolutionary history of foraging and predation should have had on the priorities built into human visual attention. To test this hypothesis, we used the change detection paradigm, in which subjects are asked to spot the difference between two rapidly alternating natural scenes. This paradigm is famous for eliciting change blindness—a condition in which observers are unaware that the scene is changing, even when major changes are introduced. (E.g., whole buildings can repeatedly appear and disappear without the subject noticing.) We discovered that change blindness is limited to inanimate objects. We found, as predicted, that animals are treated differently by visual attention.

In this paradigm, the only task subjects are given is to detect changes, so they are free to follow their own inclinations in attending to different entities in photos of complex natural scenes. Our experiments show that they are faster and more accurate at noticing changes in animals (and humans) relative to changes in plants, buildings, tools, vehicles and other artifacts. For example, changes to a small nonhuman animal at the periphery of a complex natural scene are detected faster and more accurately than changes to a large building at a scene’s center. It is a remarkable effect, once one has experienced it for oneself. (source)

Test how your own mind detects changes in scenes here.

New’s study is useful in showing that non-animal objects attract our attention less than animal. It informs us, for example, that a stray dog might distract a driver from a red light or even an oncoming car, and we can devise preventative/safety measures from there. For that we should be grateful.

Yet the hasty presumption of an evolutionary history of “keeping an eye on predators and prey” actually neglects other possible explanations for our visual prioritization:

1. The eerieness of seeing the animate frozen by photography. A still image of a waterfall, which is normally in perpetual motion, probably would be detected quickly.

2. Anthropomorphism: our expectation of personality in animals. An image of an anthropomorphized car (Lightning McQueen) or building (Amityville Horror, or any haunted house with discernible eyes and mouth) probably would be noticed faster than animals we typically do not anthropomorphize, such as starfish or sea urchins.

3. Complexity of shape. Buildings and cars do not alter shape, but animals do when they move (wings in or out, legs back or forward, head up or down). We are likely to notice quickly a change in a non-animal object that does change shape, such as a Tilt-a-Whirl.

4. Emotional connection. Humans draw close to animals in emotional bonds. An inanimate object to which humans also bond emotionally, such as a diamond ring or baseball cap, probably would be noticed faster than an animal to which humans do not typically bond, such as a hermit crab.

Doubtless, additional explanations for New’s finding may be proposed.

To be fair, New’s research did not investigate the reasons behind differences in change detection. He made a prediction about the human mind based on a presumption of evolution, and that prediction proved correct.

Whether or not it was a lucky hit remains to be seen. Creationists could have theorized the same visual prioritization based on the ordering of Genesis, then proclaimed confirmation of six-day creation. Hindus could have theorized the same visual prioritization based on animals possessing recycled souls, then proclaimed confirmation of reincarnation. Sure enough, Darwinists brush over such nuance to declare another victory for the predictive power of evolutionary theory. The original presumption must have been correct; evolution must really be fact!

Not necessarily. Each of the four alternatives I proposed might also have predictive power — power that could nail more precisely the dynamics of how our minds prioritize what we see.

Will they be investigated? Probably not; the explanation has already been presumed. Why do we notice animals faster than other objects? Because we evolved that way.

Thus evolution functions as the “God did it” response that thwarts, rather than fuels, open inquiry, leaving us without a full explanation.

Psychology and neuroscience are excellent fields that constantly break new ground, yielding wonderful advances for humanity. I wouldn’t expect much from evolutionary psychology, however — it is the 21st century’s sophistry.

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Tags: evolutionary psychology, psychology