It’s easy to get wrapped up in the small stuff: Politics at work, your kid forgetting to walk the dog, the DVR not recording "Modern Family," etc. But from an evolutionary perspective, which places all humans squarely in the landscape of the natural world, each of us is pretty lucky to be here at all.
Thanksgiving, then, is an evolutionarily relevant holiday.
It forces us to take time to express gratitude, one of the basic social emotions (see Trivers, 1985). Gratitude can be seen across human cultural groups, and it seems to have the evolutionary function of helping people stay connected with others. When someone expresses gratitude, others take note. Social relationships in humans are partly based on reciprocal altruism, or helping others in a mutually beneficial manner. Expressing gratitude is part of that process.
From an evolutionary perspective, here is a list of six things that many of us should be thankful for:
1. Food, shelter, and the basics.
Our ancestors regularly experienced drought and famine—and it’s only relatively recent in human evolutionary history that food has become abundant for a large proportion of us. But even today, it’s not abundant for everyone. So, if you have a roof over your head and turkey, stuffing, and pie waiting for you on Thanksgiving, you probably should be thankful for all that.
From an evolutionary perspective, kin relations are critical. We share genes with all humans—actually, with all living things—but we share particularly high amounts of DNA combinations with our kin. So this Thanksgiving, be thankful for any and all kin—parents, aunts, uncles, grandparents, grandkids, siblings, cousins, even those distant cousins that you feel like you hardly know. From an evolutionary perspective (see Hamilton, 1964), kin relations are particularly special.
3. Your partner.
Long-term mates are pretty critical. If you’ve got a mate who is generally kind, reliable, and competent, you are luckier than you might realize. Among other things, long-term partners help us build supportive environments for raising our young (see Hrdy, 2009). Human offspring are notoriously helpless early on—and a strong pair-bond is evolutionarily critical for providing a solid context for cultivating the next generation in a very literal sense. So sure, your spouse might not put the dishes in the dishwasher the way you prefer, may not agree with you on every purchasing decision, and may expect you to go to parties sometimes that you don’t want to go to with people that you don’t care about—but you know what? If you’ve got a long-term mate in your life who ultimately is your partner in building and maintaining your world, you should probably thank him or her for being there for you.
4. Extended family and in-laws.
In humans, having a strong extended family, including in-laws, can be critical for building a social network. Humans evolved to depend on others, and having a strong network of extended family, and good relationships with one’s in-laws, can have all kinds of adaptive outcomes (such as helping one find work, helping one with financial support during difficult times, providing childcare when needed, helping install light fixtures, etc.). If there’s one day a year that we should suspend any and all in-law jokes, I’d say it’s Thanksgiving.
5. Your four-footed friends.
Lots of us own dogs—and there are actually good evolutionary reasons for this fact. Much evidence suggests that humans and dogs co-evolved, with humans providing dogs with some steady food sources, and dogs providing humans with protection from predators in the wild along with some other critical survival-based tasks (see Skoglund et al., 2015 and Geher, 2015). Sure, they may shed fur all over the house, woof their heads off 10 times a day, and have the occasional accident, but at the end of the day, dogs are part of human families, in a very real sense. This Thanksgiving, you know you’ll have too much leftover turkey. How about you give some to your four-footed friends?
6. Your kids.
Sure, they may talk back, leave garbage on the floor, put their homework off until Sunday night at 10, etc. But at the end of the day, from an evolutionary perspective, our kids are our most direct vehicles into the future. So instead of focusing so much on telling them that they have to be thankful this year, how about instead thanking them for all it is that they do to enrich your life.
Bottom Line: This Thanksgiving, my wife and kids and I plan to host some extended family. We’ll cook turkey, apple pie, and all that. We’ll probably overeat and fall asleep on the couches watching football games that we don’t truly care about. We’ll clean dishes like banshees. And I plan to be thankful for every bit of it.
Hamilton W.D. (1964). "The genetical evolution of social behaviour. I". J. Theor. Biol. 7, 1–16.
Hrdy, S. B. (2009). Mothers and Others: The Evolutionary Origins of Mutual Understanding. Cambridge: Harvard University Press.
Skoglund, P.; Ersmark, E.; Palkopoulou, E.; Dalén, L. (2015). "Ancient Wolf Genome Reveals an Early Divergence of Domestic Dog Ancestors and Admixture into High-Latitude Breeds". Current Biology
Trivers, R. (1985). Social evolution. Menlo Park, CA: Benjamin/Cummings.