Our bodies are marvels of evolution, finely tuned over hundreds of thousands of years to survive in harsh, unpredictable environments. But in our modern world of abundance and comfort, these same adaptations that once ensured our survival now pose significant challenges to our health and well-being. At the heart of this dilemma lies our instincts – particularly those related to food and physical activity.
What Are Instincts?
Instincts are innate, fixed patterns of behavior that are universal in a species. They’re hardwired into our biology, shaped by millions of years of evolution to ensure survival and reproduction. While we often think of instincts in the context of animals – a bird’s instinct to build a nest or a salmon’s drive to swim upstream – it’s crucial to remember that we, too, are animals, subject to the same evolutionary forces.
Consider the following examples from the animal kingdom:
- A squirrel’s instinct to gather and store nuts for winter
- A mother bear’s instinctive protectiveness towards her cubs
- The migratory instincts of birds that guide them across continents
These behaviors aren’t learned; they’re encoded in the DNA of these species, ensuring their survival across generations. Humans, as part of the animal kingdom, are no different. We have our own set of instincts that have been shaped since the emergence of Homo sapiens around 300,000 years ago.
Our bodies are essentially the same as those of our ancestors from 300,000 years ago. While our societies and technologies have advanced rapidly, our biology – including our instincts – has remained largely unchanged.
Human Instincts: A Brief Overview
Humans possess a wide array of instincts, many of which played crucial roles in our survival as a species. Some well-known human instincts include:
- The fight-or-flight response
- Maternal instinct
- The instinct to seek social connections
- The startle reflex
- The instinct to learn language
While all of these instincts have shaped our evolution and continue to influence our behavior, two categories of instincts are particularly relevant to our discussion of health in the modern world: those related to food and physical activity.
Energy-Centric Instincts: Food and Activity
Our ancestors lived in an environment of scarcity, where finding enough food to survive was a constant challenge and physical activity was a necessity, not a choice. This reality shaped a set of instincts centered around energy conservation and acquisition. Let’s explore these instincts and how they manifest in our modern lives.
1. Minimizing Energy Expenditure
One of our most powerful instincts is to conserve energy by minimizing physical effort. In our ancestral environment, this instinct was crucial for survival. Every calorie burned meant one less calorie available for vital functions or to sustain us through periods of food scarcity.
Today, this instinct manifests as our tendency to:
- Choose the elevator over the stairs
- Drive short distances instead of walking
- Spend hours sitting rather than moving
Our bodies have evolved to be very efficient at retaining as much energy as possible. This efficiency, once a survival advantage, now contributes to our increasingly sedentary lifestyles.
2. Avoiding Discomfort
Closely related to energy conservation is our instinct to avoid discomfort. Discomfort, whether it’s being too hot, too cold, or experiencing physical strain, requires energy to regulate or endure. Our bodies are programmed to seek comfort as a way of conserving energy.
This instinct leads us to:
- Rely heavily on climate control in our homes and workplaces
- Wear shoes that prioritize comfort over foot health
- Avoid physical challenges that might cause temporary discomfort
For example, walking barefoot requires more calf activation and overall body engagement than walking in cushioned shoes. Our instinct to seek comfort pushes us towards the easier option, even if it’s less beneficial for our long-term health.
A real-world manifestation of this instinct can be seen in the popularity of ultra-cushioned running shoes. Despite studies suggesting that heavily cushioned shoes may actually increase injury risk by altering our natural gait, many runners choose them for their perceived comfort. This choice, driven by our instinct to avoid discomfort, may ironically lead to more discomfort in the long run.
3. Craving Calorie-Dense Foods
In an environment where food was scarce and unpredictable, the ability to quickly consume and store large amounts of energy was a significant advantage. This has left us with a strong instinctive attraction to calorie-dense foods, particularly those high in fats and sugars.
Our bodies evolved to crave these energy-rich foods because they provided the best chance of survival in times of scarcity. Today, this instinct drives us towards processed foods, sugary snacks, and fatty meals, even when we have constant access to a variety of nutritious options.
This instinct is starkly illustrated by the global rise in sugar consumption. According to the World Health Organization, global sugar intake has tripled over the past 50 years. In the United States alone, the average person consumes about 152 pounds of sugar per year – a stark contrast to the estimated 4-7 pounds consumed annually by our ancestors.
4. Overeating When Food is Available
Perhaps one of the most challenging instincts in our modern environment is the drive to eat as much as possible when food is available. Our bodies are incredibly efficient at digesting large amounts of food and storing excess energy as fat.
This instinct served us well when feast or famine was the norm. Today, in a world of constant food availability, it contributes to overeating and obesity. Our bodies are still prepared for potential periods of scarcity that, for most of us in developed countries, never come.
A vivid example of this instinct in action is the phenomenon of buffet dining. Studies have shown that people eat 45% more food when presented with a wide variety of options in a buffet setting, compared to a standard meal. This overconsumption occurs regardless of hunger levels, demonstrating how our instinct to eat when food is abundant can override our body’s actual nutritional needs.
The Challenge of Overcoming Our Instincts
Understanding these instincts is the first step in addressing the health challenges they pose in our modern world. However, overcoming them is not a simple task. These are not mere habits or learned behaviors – they are deeply ingrained, automatic responses that have been reinforced over countless generations.
Our instincts operate at a level below conscious thought. They’re quick, powerful, and often override our rational decision-making processes. This is why, despite knowing the health benefits of exercise, we still find ourselves choosing the couch over a workout. It’s why we reach for a sugary snack even when we’re not hungry.
Moreover, our modern environment is often designed to cater to these instincts. Fast food, labor-saving devices, and comfortable, sedentary entertainment options are all around us, making it even harder to resist our instinctive drives.
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