In the first part of this series (here) I reported on the fact that a few of my coworkers had taken to saying that I had become more of a "jerk" in the time since I had lost some body fat and gained some muscle. I also reported that the same thing had happened to a client of the gym. I went on to outline a number of possible reasons for my increased, we'll say for the sake of brevity, "aggressive" behavior and some possible reasons for my coworkers increased, again we'll say for the sake of brevity, "sensitivity".
The second part of the series (here) was devoted to the rebuttals of said coworkers and my responses to those rebuttals. That part of the series was a joke more than anything. The coworkers in question are great friends of mine and I have a lot of respect for their opinions on a lot of things. But when someone lobs you a softball right down the middle sometimes you just gotta hit that fucker out of the park and stare down the pitcher as you slowly round the bases and then defiantly stomp on home plate. But on the the third part, Bringing It All Together.
In the first part of the series I led people to believe that testosterone influences aggressive behavior. This is a stereotype that a lot of people and a lot of scientists assume to be true. It is actually murky at best. While there are many studies showing a correlation between testosterone and aggressive behavior, causality has never been proven.
If you break down aggressive behavior further into hostility and sensation seeking you are more likely to see a direct effect of testosterone levels and people who like to skydive and race cars than people who get into fights and mock their coworker.
Another factor is that testosterone is just one hormone. There are dozens doing an intricate dance in your body at any given time. It is very difficult to study the behavioral effects of one thing (hormones, stress levels, societal influences, etc.) while controlling for all the others. To say that when ABC happens with testosterone then XYZ happens with behavior shows a correlation at best but is flat out wrong at worst.
Digging deeper is the fact that some people are more responsive to certain rises and falls in their hormones than others. A study that looked at a modulator of androgen receptivity found that there were significant interactions between CAG repeat length (the modulator for androgen receptor sensitivity) and testosterone. There were signs that a longer repeat length led to certain behavior and a shorter led to others. To make this clearer it wasn't the hormone itself, or even the receptor for the hormone that influenced behavior, but the modulator for the androgen receptor sensitivity. That's three link down the chain of command if you think about it.
Now let's take a look at how the actual levels of androgens themselves effect behavior. In Dr. Robert Sapolsky's excellent book, The Trouble With Testosterone he did exactly that. In the title essay he looked at a number of studies done on humans and animals that led to some interesting conclusions that have been missed by much of the lay public.
Instead of rewriting what Dr. Sapolsky has already written I'll just get to the main points. Many studies have shown that when males are placed in a group together basal testosterone levels predict nothing about who is going to be aggressive. It's behavior that drive the hormone secretion rather than the other way around. Let that sink in. Testosterone secretion doesn't drive aggressive behavior. Aggressive behavior drives testosterone secretion.
In studies (I only hope on animals) where the testes are removed aggressive behavior drops. But when testosterone is readministered to only 20% of precastration levels the same amount of aggressive behavior occurs. The same thing happens when testosterone is administered to 200% of precastration levels. The brain can't tell the difference. There is more to this argument, but the proof is right there in the pudding. There is no way I've increased my testosterone production to twice what it used to be. I don't know because I've never had them checked but I'm fairly certain that the things that I've done have made a difference, but not even that big of one.
Now, for the sake of the argument let's say that I did. And let's say that I did in a big kind of way. A study was done where a group of monkeys were placed together and given time to sort out a social hierarchy. The researchers then took the number three monkey (He was number three out of five. This meant he could boss around numbers four and five, but took marching orders from numbers one and two.) and gave him four times the amount of testosterone he had at normal levels. This monkey was probably pissing testosterone. A very interesting thing occurred. Instead of making power plays and going beast mode on numbers one and two he ended up just being a colossal prick to numbers four and five. He still ate crow when it came to numbers one and two. What does that mean? Testosterone exaggerates aggressiveness not cause it.
This is where you get into the tricky business of mixing behavioral biology and outside environmental and societal influences. To say that a biological ABC causes a behavioral XYZ means nothing if those other factors aren't taken into account.
So what does this mean for me and why I'm a jerk? To put it simply I am, always have been, and always will be a jerk. Especially to Lance and Jake. Those guys are total jerks.
Sources:
The Trouble With Testosterone. Robert M. Sapolsky. 1998.
http://www.ncbi.nlm.nih.gov/pubmed/16136009
http://www.ncbi.nlm.nih.gov/pubmed/15179027
http://www.ncbi.nlm.nih.gov/pubmed/20479013
http://www.ncbi.nlm.nih.gov/pubmed/20816841
http://www.ncbi.nlm.nih.gov/pubmed/18505319
http://www.ncbi.nlm.nih.gov/pubmed/10097017
http://www.ncbi.nlm.nih.gov/pubmed/15795710
http://www.ncbi.nlm.nih.gov/pubmed/19054624
http://www.ncbi.nlm.nih.gov/pubmed/21382439
No comments:
Post a Comment