Testosterone is a hot topic in today’s society. The male hormone and subsequent theories and myths (often inaccurate at best) surrounding it are common subjects of discussion, especially when libidos, impotency or aggression are involved in the conversation. Low testosterone levels is marginalized as something to pity in a man – but research has suggested testosterone levels in humans is decreasing…and we may actually be thankful for this trend…
Nathan H. Lents, Ph.D., is a professor of Molecular Biology at John Jay College, of the City University of New York, where he is also Director of the honors program and the Macaulay Honors College. He is the author of Beastly Behavior and Not So Different: Finding Human Nature in Animals. He sheds some light on the links between testosterone and evolutionary psychology, and why the evidence appears to suggest a general decline in testosterone may have, indeed, paved the way for civilization as we know it.
What were the most interesting finds highlighted in your book, ‘Not So Different: Finding Human Nature in Animals’?
There were a lot of surprises as I researched the book. I was surprised at how broadly and deeply animals grieve. I was surprised at how enduring animal pair-bonds can be. I was also surprised at how easily some human behaviors can be analyzed in basic evolutionary terms. We really aren’t as complex as we think we are. We have a swirl of complex culture, but our behaviors are driven by very basic desires and instincts.
In light of your article highlighting the chronological differences in testosterone as humans have evolved over time, do you think Machiavellian behavior has, in general, decreased over time? Are we seeing a transition from an individualistic culture to a more egalitarian civilization (cultures may vary…)?
Well, I think although we are mixing two things here on two different time-scales, the outcome is still the same. The short of it is that, yes, I think that the transition from archaic Homo sapiens to modern competitive instincts and a move toward more cooperative instincts and behaviors, at least under the right circumstances. This was a genetic and heritable change, driven by natural selection. I also think that human society has become less prone to interpersonal violence as we made the transition from hunter-gatherers to agrarian, and from agrarian to state-based societies, and from early states to modern states. This has not been a genetic change, however, but rather a crafting of the societal and cultural millieu in which we learn to behave. We have created domestic and lifestyle structures that activate our more cooperative nature and inhibit our more competitive one, or at least redirects it to socially beneficial or at least acceptable outlets. Steven Pinker, Michael Shermer, and other have written about this and the data is pretty overwhelming that both interpersonal violence and warfare-based violence has been a slow and steady decline since the earliest days of settled life. I think we domesticated ourselves in the first step, the genetic step, and then we’ve been training ourselves in the second step. That’s my thinking on it anyway. By the way, yes of course there are cultural variances, but most of these trends cut across cultures quite nicely. We have much more in common than in contrast.
You’ve mentioned in previous interviews/articles that hyper-competitive, territorial antisocial mammals tend to have high levels of testosterone. Do you think those findings could be replicated in aggressively territorial social circles – perhaps, say, in nationalists, or even the KKK…?
In that line, I was talking comparing species to each other, rather than individuals. Species with high circulating testosterone tend to have a more violence- and dominance-based social life, whereas those with lower levels tend to live more harmoniously. We must also admit that either one can be an effective strategy in different circumstances. As hippy dippy as I am, and as much as I yearn for a violence-free existence for me and my fellow humans, there is no point in denying that competition and violence can be good strategies for members of any species under the right circumstances. I think this underscores the value of the social engineering that we’ve accomplished – we’ve done a lot to ensure that violence doesn’t pay and that cooperation does. We can do more. And I hope we do.
As for your question about individuals with tendencies toward racial in-group identification (or let’s just call it racism), xenophobia, etc., I would not bet any money that, as a group, they have higher testosterone, although I wouldn’t be shocked if it was found that they do. Instead, what we know about racism is that segregation and self-seclusion from people in different groups (this can be race, religion, sexuality, etc.) leads to these kinds of anti-social feelings toward those that are different. So I think what is going on is more that the activation of empathy and cooperative instincts happens only in that very insular social context. If you don’t grow up around people from certain groups, you don’t form the bonds of empathy with them that lead you to see them as someone you might want to get along with.
Evolutionary theories imply females typically prefer males with high levels of testosterone, in order to better protect their offspring. Do you think these theories are now redundant in today’s society, given the general decline…or is it still as valid as ever? (Assumption of heterosexuality is widely applied in evolutionary theories of sexual preference, and carried through in this question.)
It’s pretty well established that some of the physical effects of testosterone lead to traits that heterosexual women rate as attractive such as being tall, having facial hair, broad shoulders, and so forth. However, too much testosterone gets men into trouble and women know that, so there is a balance there. I don’t think this has been studied enough to say too much to be honest.
In your article, you mentioned the differences in dispute resolution between common chimps (typically patriarchal) and bonobos (matriarchal). Would you say the research appears to suggest that high testosterone males should perhaps not be leading countries, and instead we should leave it to cooperative females? (I’m hoping we exclude the relationship-restoration-by-sexual-favor behavior you noted…)
Well, we can all name countries that have been brought to ruin or nearly so by the poor choices of ultra-competitive men who were acting as much out of ego-driven power lust than a desire for the best rewards for his country. Women are not totally immune to this, of course, but the most power female leaders the world has known, whatever individuals faults they may have had, have been very effective and well-regarded by their countrymen, their neighbors, and their adversaries. I don’t like Margaret Thatcher’s politics, but she was very skilled and I think people really believed in the principles she fought for. Angela Merkel is emerging as the most powerful world leader in Europe but without any form of “Germany-first” posturing. I may be biased on this point, but I look at the world today and for the last half-century and I see every brutal dictator being male, while the admittedly few women have risen to power in their countries have been noted for their strong, collaborative, and mostly selfless leadership.
Despite the findings being incredibly deterministic, in the sense that there’s an implication of absence of free will, would you say that to have higher levels of testosterone essentially causes more harm than good to a community?
I don’t think it’s necessarily deterministic. These are complex traits – they are probabilistic. Higher levels of testosterone might make it more likely that you are violent, but there are many other factors as well, some under your control, some not. When you take these probabilistic features and blow them up to population scale, it becomes more of a direct correlation, but that doesn’t determine how individuals will and won’t behave. And yes, I would say that, in human society, from early to modern, high levels of testosterone do more harm than good for the community (even if some individuals benefit from time to time).
Why is it, do you think, that many people would prefer to struggle on their own, than to ask for help in order to succeed? Why is reaching out for help often seen as failure?
I have a great deal of anecdotal experience that that is a testosterone-driven trait. I think there may be something to that, actually. Young males often engage in displays of fitness to advertise their biological fitness to potential mates. Asking for help would serve to undo all that. I don’t think it’s a coincidence that males, particularly young males, are the ones that are resistant to asking for help.
What are you currently working on, or planning to be working on in the near future, with regards to molecular biology?
In my lab, we are currently finishing up a project on forensic botany (I have eclectic research interests!). In short, we developed a DNA-based method of determining the species of origin for plant residue left at a crime scene. This is a first step toward developing full DNA “fingerprinting” of household flowering plants. I teach in a forensic science program so I take masters students from that program and we need to come up with projects that are relevant to their career goals. They are usually very fun also!
How long have you been studying molecular biology, and have you always been focused on this field?
I got my first job in molecular biology while still in college, I guess it was 1997 or so. That was engineering bacteria to over-produce and export amino acids to be used as additives in livestock feed. I then worked on soybeans and their chief parasite, the soybean cyst nematode, before focusing on human biology in graduate school. Since 2000, I’ve mostly been studying human biology at the molecular and cellular level, but I’ve always loved physiology and psychology and I don’t see them as separate.
In a previous interview with us, you alluded to the possibility that civilization may have been a gradual process of humans domesticating ourselves. Does this offer a potentially deterministic perspective on high-testosterone aggressors, especially in a criminal sense? Is it possible to differentiate between free will and determinism, or would you say that the biological basis (having high testosterone) only potentially enables the likelihood of acting aggressively?
Definitely the latter. As I said above, these are complex traits and behavior is probabilistic not deterministic. Even if there is no such thing as free will, from a practical point of view, we have to act as though there is. We know that we can coerce good behavior and dissuade bad behavior through the establishment of rules, rewards, and consequences. Even if there is no free will involved, actions have to have consequences or we lose our ability to shape behavior. If a murderer claims that, in that moment, he acted only in such a way as his prior experiences would have dictated anyone to act, we have to say, “Well, that’s too bad, but you’re going to jail because if you don’t, others will be emboldened and you’d probably kill again also.” Now, that’s not to say that we should be harsh and unforgiving. Quite the contrary. Research has shown that the more restorative and rehabilitative our approach to punishment is, the better outcome for all. I don’t see a conflict in how we approach these issues in terms of whether or not we have free will. Either way, we want to set the stage for good, pro-social decisions.
Finally, a potentially controversial question to end on. Some of your research involves animals. What is your view on animal testing for scientific gain?
I have a complicated view on that, but let me first say that I have never done any research on living animals. I have assisted in the authorship of papers detailing research that involved animals, but I wasn’t personally involved in the research and only got brought onto the team when it was time to analyze the data and write the manuscript (a specialty skill of mine). I think that animal research, if and when it happens, should be as humane as possible, and that the line of what qualifies as inhumane needs to be dramatically moved. I also think that animals should be handled and boarded in a more humane and stimulating way. Having worked in medical centers with animal research facilities for seven or eight years, I have seen some things that I would characterize as cruel and disturbing. However, none of it comes close to the food industry and factory farms. I don’t think that all medical research involving animals is inhumane, but a great deal of it is. However, as a social movement, I think the more achievable gains are in the housing and care of our food animals.
I would like to thank Nathan for giving us the time to conduct this interview. His answers have certainly shed some light on how important testosterone can be in the grand scheme of all things involving civilization and human behavior – which happens to be pretty much everything regarding humans…