Is Cultural Evolution Out-Running Our Brains?

Are we big-brained mammals who have out-evolved ourselves?

'The evidence for the hypothesis that cultural evolution is faster than biological evolution is anecdotal...and there are no systematic comparisons of cultural and biological rates of change. Moreover, we do not know how much faster, if at all, culture can change compared to biological phenotypes." (Charles Perreault, The Pace of Cultural Evolution)

I constantly hear people say things such as, "I can't keep up with what I need to do," "I can't keep pace with what's coming in," "I'm always frustrated because I'm falling behind," "Time is moving too fast—faster then ever," "I have all these devices to do things for me, but I still feel overloaded," "I'm exhausted with all that I feel I need to do or am expected to know," or "I feel so dumb."

After a long discussion about cognitive and emotional fatigue, a friend simply asked, "Are we big-brained mammals who have out-evolved ourselves?" I was taken in by his question and began to wonder if it's because people who argue that cultural evolution moves faster than biological evolution are correct and that our brains just can't keep up with all that's coming in. For example. might it be the constant inflow of information, disinformation, and other sorts of distractions into email inboxes that makes so many people feel frustrated and like they're always falling behind. This could happen regardless of the accuracy or importance of what's readily available.

As I was doing some research on the general topic of comparative rates of cultural versus biological evolution, I came across a recent essay called "How Culture Makes Us Smarter." Even before I read it and some of the comments posted by readers, I wondered if this was really so and how words such as "smart" and "intelligent" were being used. In this piece we read, "Cumulative culture doesn’t just gift our species technology that none of us could have invented; it literally makes us smarter." Smarter than whom, I wondered? Along these lines, we're also told, "Humans are smarter than chimps and all other animals, and that’s why we can go to the moon but they can’t."

Two thoughts come to mind. First, I'm always leery of cross-species comparisons in intelligence. I'm frequently asked questions that center on species differences in intelligence — are dogs smarter than cats, are birds smarter than fish, for example. I always say that nonhuman animals have to be able to do what's needed for them to be "card-carrying" members of their species, and we must remember that numerous nonhumans outperform us in many different ways. So, the question about comparing different species doesn't mean much to me and I've argued it's pretty much biologically irrelevant. (See "Are Pigs as Smart as Dogs and Does It Really Matter?" and "Are Dogs Smarter Than Cats?")

Second, are we really smarter because of cumulative cultural changes and because of this, also smarter than other animals in ways that give us an evolutionary advantage? I don't think so given what we now know. For example, I can't find any objective measures that enable us to make meaningful cross-species comparisons relating cultural evolution and so-called intelligence. We and other animals do what we need to do to survive and to thrive. "Being smart" is species-relative and individuals of other species do just fine in their own social and other niches—some doing at least as well or even better in their environs than we do in our own human environs. That chimpanzees can't go to the moon might not be all that important after all.

Also, if we're smarter, do these differences really make a meaningful difference in adaptability and individual fitness? In an essay called "Why does culture increase human adaptability?" we're told social learning doesn't necessarily increase fitness, but it can be adaptive "if it makes individual learning more accurate or less costly." There's no reason to assume that humans are exceptional in this arena.

Cultural versus biological evolution

"...given enough time, cultural evolution will lead to increasingly larger 'morphological' changes than biological evolution, potentially allowing for better accommodation to selective challenges." (Charles Perreault, The Pace of Cultural Evolution)

Thinking about "How Culture Makes Us Smarter" got me back to thinking more about how cultural evolution might be out-evolving our brains' ability to deal with all the constant and diverse input. Rather than making us smarter, it's responsible for all sorts of frustration associated with being unable to keep up with everything that's coming in and making some people feel dumb.

My search for essays on rates of cultural and biological evolution resulted in finding an interesting essay by Dr. Charles Perreault called "The pace of cultural evolution" in which he notes that this assumption has never been empirically tested and that it's really not all that obvious. This really surprised me, because the inverse relationship between cultural and biological evolution in which it's often declared with little or no hesitation that the former goes faster than the latter has become an oft-cited meme. According to Perreault, there's no scientific reason for assuming this is so. I was intrigued.

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Perreault's essay is available online, but for those who haven't thought much on the topic at hand, his summary is right on the mark. He writes, "Cultural evolution is expected to be faster than biological evolution because of its Lamarckian nature, and because cultural information is transmitted through different routes than genetic information. While variation in biological evolution arises from random mutations, Lamarckian-like guided variation, which occurs through modifications to knowledge, skills and technologies made by an individual that are subsequently transmitted to other individuals, is a potent source of cultural variation [3], [5], [7], [15], [16]." (Numbers refer to his references.)

To test the rates of change of cultural and biological evolution, Perrault compared how rapidly human technologies change with how rapidly animal morphologies change. He's well aware that he's assuming that rates of change in technologies and rates of morphological change are representative of cultural evolution and biological evolution, respectively.

After controlling for the effects of different variables, Perrault concluded that cultural evolution is indeed faster than biological evolution regardless of the generation time of a species. He also notes, "...it is unclear as to what extent these findings can be extended to other domains of human cultures, such as social norms, institutions, or political structures, or compared to known rates of change in language [53]–[55] and performance of modern information technologies [56]."

Where to from here? Is cultural evolution out-running our brains?

To answer this question, we need data that look at rates of cultural evolution and our brain's ability to deal with what's coming in. We also need information on how widespread is the feeling that humans simply can't keep up with different sorts information, distractions, and other sorts of overload with which they're constantly bombarded, and that, in fact, we've already out-evolved our brains or are well on the way toward doing so. I expect these feelings will vary from culture to culture.

My guess is that our fired up brains can't keep up with everything with which they're constantly subjected and that this feeling is wreaking havoc on the quality of life for far too many humans. It also will be interesting to learn how some people adapt to the incessant input and do just fine.

Stay tuned for further discussions and speculations about possible relationships between rates of cultural and biological evolution. These exchanges not only are exciting, but also can help us understand where we might be heading in the future. I wonder if our brains will ever be able to catch up with cultural changes, and if not, what this will mean for future humans.