One of the running themes of Micromotives has been the examination of the myriad cognitive, perceptual, psychological, and social factors which interact to influence the quality of our decision making processes, especially those which are not captured in the traditional economic models of perfectly rational actors. We have a lot to learn from evolutionary psychologists, who point out that much of modern human behavior evolved between 500,000 and 100,000 years ago in our ancestral environment of the African savannas. Behaviors which made one more likely to survive in that environment (and thus procreate, spreading the genes for those behaviors further) do not necessarily equip us with the right tools for survival in today’s world. One common example is the strong desire humans have for sweet and fatty foods. This made sense thousands of years ago, when the majority of humans were locked in a daily struggle to find enough food to survive. Gorging on the fatty meat of a kill made sense when it wasn’t clear where your next meal would come from, nor could you refrigerate the “leftovers” and eat them tomorrow. Building up a calorie surplus in the form of an extra layer of fat was a strongly adaptive tendency. Yet today, especially here in America, where food is hyperabundant and relatively few are at risk of starvation, those same behaviors which served us well on the savannas now lead to obesity, heart disease, and higher mortality rates. The fundamental point is that while the process of evolution has produced some staggeringly complex and effective survival strategies in humans, it has not left us perfectly tuned for how the world works at this very moment; rather, it has tuned us for how the world has worked on average over a broad swath of the past. Biological evolution is a very slow process when viewed from the perspective of a human lifespan.

All of that serves as an introduction for an interesting new study appearing in the British Journal of Psychology which found that hungry men are more attracted to heavier women than those who are satiated.

In some societies where food is a limited resource, such as the South Pacific, higher body weights are revered. In others where food is abundant, such as the West, lower female body weights are preferred.

Evolutionary psychologists believe this is a survival preference. What you are looking for in a mate is the best chance of healthy offspring and in an environment where food is scarce, a heavier woman is deemed a safer bet for this.

What can be regarded as a normal and acceptable body size is also influenced by what we see, including advertising, and can change. For example, migrants from rural to urban societies show an increasing idealisation of thinner figures.

The bottom line from a Micromotives perspective? Even fleeting physiological factors (”is it just before lunch, or just after?”) can bias our thinking in significant ways.

Read more: Hunger dictates who men fancy

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