10 Ancient Rules We Should All Live by Today

Understanding the lessons of evolution can help us lead richer lives today. 

Any good framework for understanding human behavior should have applied potential. A good psychological theoretical framework should provide a road map to how we can improve such domains of the human condition as physical health, mental health, education, government, and so forth. I think that a good framework for understanding human behavior should provide some kind of personal roadmap. In other words, a good theoretical perspective in psychology should help us understand not only our broader social world, but also our personal world—and help us live a better life.
As I’ve written extensively, evolutionary psychology has the capacity to help us gain enormous insights into the human condition (Geher, 2014 (link is external)). Following are 10 ways that evolutionary psychology, which has emerged as the single most powerful explanatory framework in the behavioral sciences, can help guide our personal lives in positive ways:
1. Follow human universal moral codes.
Most humans are explicitly religious (Wilson, 2002 (link is external)). Amazingly, in spite of all the conspicuous differences among various religions, there are extraordinary universals among them. As David Sloan Wilson famously pointed out, all religions serve to encourage people to sacrifice their selfish interests for the good of the broader group. Along with this general tendency are universal moral codes—codes that not only exist across many religious groups, but also seem to typify human psychology regardless of whether someone is “religious” or not (Trivers, 1985). Across all human groups, inflicting costs on innocent others is frowned upon. So is taking more than one’s fair share of a resource, and contributing less than everyone else in a group. These facts, which characterize our “groupish” species across the globe, help us understand human evolved moral psychology. That knowledge can help us thrive in the many group contexts in which we find ourselves.
2. Prioritize family.
A landslide of data on human social behavior shows that family matters. Humans, like many species, demonstrate kin-selected altruism—the tendency to show biased prosocial behavior toward genetically related kin (offspring, siblings, cousins, parents, aunts, uncles, grandparents, etc.). Blood is very thick, and evolutionary psychology helps us understand why. Call your parents. Love your children. And stay in touch with your cousins. Your kin network is a unique, inescapable, and deeply important element of your life.
3. Focus on friendships.
When Trivers (1971) developed the idea of reciprocal altruism as a basic part of our evolved psychology, he nailed it. Humans live in stable social groups for long periods of time, and we recognize and remember individuals. Developing friends (independent of kin) is an essential part of our evolutionary heritage. Don’t blow it! People evolved to help non-kin—with expectations of being helped in return—and we evolved to have expectations of such relationships between reciprocating individuals last for a long time. So be a loyal friend, like the most successful of our ancestors surely were.
4. Don't forget to love.
Love takes on various forms across cultures and kinds of relationships. But, at the end of the day, it’s a human universal. Mating systems that resemble some form of monogamy are common across the globe. The universal emotional experience of love provides the psychological and (oxytocin-based) physiological glue that keeps couples together. It also allows them to work as collaborators in raising such altricial (i.e., needy) offspring as we find in our species (Fisher, 1993). Love is a wonderful thing, and clearly a basic part of our evolved heritage. Make sure that you have plenty of it in your life.
5. Expect a long social life.
In some species, such as beavers, an adult animal can go months without seeing a conspecific (a member of its same species). In other species, such as North American crows, animals see the same individuals day in and day out, across seasons and years. Humans are more like crows than beavers. In such species, animals form relationships. They come to rely on one another for help in such tasks as finding and sharing food. What’s good for one animal is often good for others in the group—regardless of kin lines, in many cases. Humans are perhaps the world’s leading prototype of a species that has a consistent social group across long periods of time. Let this fact help guide your interactions, and you’ll benefit accordingly.  
6. Expect a long physical life.
Some species show brief, fast-lived lives (such as drosophila, or fruit flies). Some have lives that are decades long. In species with short lives, evolutionarily optimal strategies are designed for such timeframes—a plan of developing quickly and reproducing frequently, for example, makes evolutionary sense. In long-lived species, such as humans, such fast-reproducing strategies are not evolutionarily optimal. In a slow-developing and slow-reproducing species such as ours—what biologists call a k-selected species—taking time to form healthy and trusting long-term relationships across the lifespan is evolutionarily essential.
7. Treat others like you live in a world of 150 people.
Under modern conditions, we are often surrounded by strangers we’ve never seen before and will likely never see again. (Think of being on a train in a foreign country.) Under ancestral conditions, that typified hominid evolution for thousands and thousands of generations, humans rarely encountered any individuals outside their own clan. These clans were stable groups including both kin and individuals with long-standing relationships with clan members, typically totaling about 150 individuals (Dunbar, 1992). If you were only going to see the same 150 people—and only them—for the next 40 or so years, how would you treat them? Kindly, of course!
8. Get out into nature.
For over 99 percent of our evolutionary history, there was no such thing as an office building, a car, a train, a house, or a computer. Our ancestors lived in nature. Always. They were exposed regularly to sunlight, vegetation, animals, and features of the natural landscape like rivers, trees, and mountains. Today we spend too much time inside and too little time out in nature. Such modern problems like Seasonal Affective Disorder likely relate to this classic evolutionary mismatch. So take a hike, run outside, take out a canoe, take the kids to the beach, or climb a mountain. You’re unlikely to regret doing any of these things.
9. Eat, exercise, and live naturally.
One of the great insights of modern evolutionary science relates directly to health: Our modern lifestyles mismatch ancestral conditions, which has led to dramatic health consequences both mental and physical. A lack of evolutionarily typical social environments, such as modern people living far from their extended kin, has consistent adverse mental health effects, like loneliness and isolation. Similarly, a lack of natural levels of exercise—our ancestors covered miles and miles a day for generations—leads to such adverse physical health outcomes as obesity and heart disease. And a lack of natural foods in one’s diet similarly leads to such adverse health outcomes as Type-II diabetes and premature death. Our minds and bodies were adapted to small-group living in the natural African savanna environment, eating only non-processed foods. To the extent that we can replicate significant aspects of this kind of environment, we are doing ourselves a favor. Otherwise, we risk living an unhealthy mismatched life, like a monkey in a cage at a zoo.
10. Cultivate life.
Evolution has nearly everything to do with life, and cultivating life matches much of what’s in our evolved minds. Parenting is a form of cultivating life that is easily understandable from an evolutionary perspective. Putting time and care into one’s offspring is, perhaps, our evolutionary goal sine qua non. But there are lots of other ways to cultivate life, all tapping into our evolved tendency to nurture. Such examples include working as a teacher or camp counselor, working in the “helping professions” such as social work, taking on foster children or foster pets, or working on community-based initiatives to improve the environment. (Or, as I do each summer, you can plant a vegetable garden, care for it, take out the weeds, fend off the critters, water it, and watch it grow.)