Evolution: The Slow Life Hypothesis and It’s Applicability (or Not) In Human Beings

What is the Slow Life Hypothesis?

Greatly simplified one aspect of the slow life hypothesis (itself an aspect of evolutionary life history theory) of evolutionary biology. says that as resources become more and more abundant species adapt/evolve a strategy of delayed maturation and take longer and longer to reach sexual maturity. A corollary of the theory suggests that these species take longer and longer to reach social maturity as well, and often display adolescent or even pre-adolescent behaviors at ages that were once considered hallmarks of adulthood. Finally, the theory also postulates that these species become more and more risk averse and tend to favor long term survival strategies over those that may deliver big rewards in the short term but are high risk. There is (limited) evidence for each aspect of the theory as described above in various animal species. The first postulate is by far the most well studied and the (only?) for which direct evidence has been published. The question I wish to address is if this hypothesis also applies to human beings, and, if so, what might the implications be for our long term survival as a a species. (Philosophers of science will no doubt take issue with the appropriateness of my usage of the terms hypothesis and theory in this post. I tend to go back and forth between the two suggesting an equivalence where there is only a relationship. My selection of the use of either term was based on what sounded better at the time and I am happy with the final result of my choices.)

The New(ish) Data

Recently a very large survey study by Twenge et. al published in the journal Child Development provided data that seemed to support the hypothesis and its applicability in humans. (apologies for lack of link here. Google it and you can find it.) The study compiled data from seven surveys of 8.3 million 13 to 19 -year-olds between 1976 and 2016 and mostly focused on behavioral questions related to various aspects of risk and risk taking. Questions about sexual activity, drug taking, parental disobedience and the like were abundant. A very high level view of the data in sum showed a significant decrease in virtually all risk taking behaviors within the cohort studied. Importantly these decreases cut across socio-economic lines and were virtually identical in magnitude and scope for rich, white teens, and poor, non-white ones, alike. It will probably surprise no one to learn that when the researchers looked at what activities the adolescents were mostly ‘substituting’ for the risky ones, texting and other social media related emerged as the most popular by far. Other data (not the focus of this publication) have shown that adolescents are overall participating in less “adult” activities such as summer jobs or moving out of their parents homes, or postponing these things until later and later ages in life. These trends are also being seen in all socio-economic brackets though they are more pronounced among the wealthy white adolescent population, particularly in the developed world.

It is hard not to read these data and others like it as strongly supportive of the slow life hypothesis and its applicability to human beings. Resources have continued to become more and more abundant, particularly in the United States and developed world. At the same time we see our youth population clearly decreasing its appetite for risk and taking longer and longer to participate in ‘adult’ rites of passage like job taking and moving out of home. I am not certain I completely agree with that interpretation (to take only one example, the trend for sexual maturation, at least for females, is going in the exact opposite direction of what the theory suggests. Hormones in the water, or other environmental factors have been posited as explanations for this but nevertheless the reality runs counter to what the theory predicts, no matter the reason), but for purposes of the remainder of this piece I will accept that view as essentially correct. Assuming that the human population (at least in the United States and developed world) has now entered into the ‘slow life’ phase of evolution what might that mean for our future as a species? On balance should this be considered a net positive, net negative, or net neutral/no effect, in terms of our long term survival and overall health/physical well-being and mental health/(happiness)?

Impacts on physical well being

I mention both health/fitness and mental health intentionally because in this instance I believe they are headed in opposite directions or at least not the same direction. In terms of our long term survival as a species, I do not see any real downside to a slow life strategy in humans from a health/fitness perspective. We are and will remain at the top of the food chain no matter how ‘slow’ our lives become. As many have argued and I basically agree technology has allowed us to essentially ‘step outside’ the bounds of evolution’s natural selective pressures. We no longer have to be the most physically fit or even the smartest to live to ripe old ages, reproduce, and pass on our genes. All that is required is our technology and the ability to continue to make and use it to our benefit. This will not change no matter how long adolescents take to move out of their parents home or how much time they spend on their smartphones instead of out having sex and taking drugs/drinking like many persons of older generations were doing at that age. On the other side of the coin I also see no major upside to the slow life strategy from an overall health/fitness perspective. In might result in a slightly extended average length of life by reducing the number of adolescent deaths by some fraction (those attributed previously to the risk taking behaviors that are no longer being pursued) but any effect would be marginal at best.

Impacts on mental well being

In contrast to physical well being/health I do think the slow life strategy presents some serious downsides in terms of our overall mental health as a species. In this instance I will specifically focus on happiness, the one aspect of our mental health I feel is most at risk from a slow life strategy. The concept of happiness is a very difficult one to discuss in a serious and thoughtful manner. It comes laden with so much baggage and peoples perceptions about what happiness is or what does or should make a person happy are wide ranging and diverse to put it mildly. Moreover, it may be the most thought about, studied, written about, and discussed concept in all of humanity other than perhaps love. This makes it literally impossible to say anything new or interesting about it. That said, just because something is not new or interesting does not automatically mean it is without value. If it did all of my writings would be worthless. Therefore I feel justified in continuing. Talking about this is made even more problematic as it involves a very broad category of people (in this case an entire generation of adolescents) and invokes extremely sweeping generalizations of which there are obviously an untold number of exceptions. It is way too easy to fall into a bad case of GOMS (grumpy old man syndrome), shake ones fist to the sky and moan “kids today…..” Those who have read any of my writings in the past know I do not take kindly to that approach. It is lazy and ignorant to lump any generation (rarely ones own of course) into a bucket then proceeds to dump on it with all the shitty things they are said to exemplify. I have mentioned the example of my own generation (X) many times, and written extensively about how we were stereotyped and so poorly portrayed in mass media and the culture at large.

Slow life and happiness

Sometimes it seems that everyone’s definition is very different and thus everyone’s concept and feelings of happiness are different, but I would suggest that this is a mistaken impression. While I do not disagree that there is a huge range of very different things that bring various people happiness I do believe the actual feeling itself, the “feeling of happiness” is very similar or identical among all persons. Moreover what it actually is to “be happy” I believe is similar or the same for everyone. Since all persons share a similar perception//feeling of happiness I think the the overall happiness of everyone can be impacted in a positive or negative fashion by factors that effect everyone or almost everyone even if this is in indirect, impossible to measure, or non tangible ways. A slow life evolutionary trend would be one such factor that I would posit could (eventually) impact every human being’s happiness in this manner. It would do this through an overall reduction in “fun” or “non serious” play among humans at earlier and earlier ages. In contrast to what one might suspect about adolescents living at home longer and engaging in less risky behaviors which would seem to increase opportunities for “healthy” “fun” it actually has had the opposite effect. According to the data from the Twenge study and others it is for a very simple reason, these risky behaviors have been replaced with mostly one thing; smart phone/computer/social media ‘play’.

I have not seen a study which asks adolescents directly if they find these activities ‘fun’ or if they make them feel ‘happy’, but anecdotal evidence abounds on the happy question suggesting it does not. Personally I would find it hard to believe that many, if not most, adolescents find these activities fun, at least in the short term. If they did not I am not sure that they could be so popular, irrespective of the supposedly irresistible effects of peer pressure. It seems that slow life leads to digital life which eventually leads to sad life for all. Depressing isn’t it.