1700 words

Many long-time readers may know of the numerous tirades of been on in regards to the “testosterone causes crime and aggression” myth. It’s a fun subject to talk about because the intelligent human physiological system is an amazing system. However, people who are not privy to the literature on testosterone in regards to race, aggression, crime, sex differences etc are only aware of whatever they read in pop science articles. So since they never read the actual papers themselves, they get a clouded view of a subject.

In my last article, I wrote about how there are no “testosterone genes”. In previous articles on the hormone, I have proven that there is no causal link between testosterone and aggression. But when comparing the sexes, how do the results look? Do they look the same with men being more violent while women—who have substantially less testosterone than men—do not have any higher levels of aggression or crime? The most recent study I’m aware of is by Assari, Caldwell, and Zimmerman (2014) titled: Sex Differences in the Association Between Testosterone and Violent Behaviors.

To make a long story short, there was no relationship between testosterone and aggression in men, but a significant relationship between testosterone and aggression in women. This data comes from the Flint Adolescent Study, a longitudinal study conducted between the years of 1994 to 2012. In regards to testosterone collection, saliva was used which has a perfect correlation with circulating testosterone. The eligibility to be included in the testosterone assay was “provided consent for the procedure, not being pregnant, not having anything to eat, drinking nothing except water, and not using tobacco, 1 hour prior to collection” (Assari, Caldwell, and Zimmerman, 2014).

The adolescent who contributed saliva gave a whole slew of demographic factors including SES, demographics, psychological factors, family relations, religion, social relations, behavior, and health. They were aged 14 to 17 years of age. They collected data during face-to-face interviews,

Age and SES were used as control variables in their multivariate analysis. For violent behaviors, the authors write:

Youths were asked how often they had engaged in the following behaviors; ‘had a fight in school’, ‘taken part in a rumble where a group of your friends were against another group’, injured someone badly enough to need bandages or a doctor’, ‘hit a teacher or supervisor at work (work supervisor)’, used a knife or gun or other object (like a club) to get something romantic a person’, ‘carried a knife or razor’, or ‘carried a gun’.  All items used a Likert response, ranging from 1 (0 times) to 5 (4 or more times). Responses to each item were averages to calculate the behavior during the last year. Total score was calculated as the average of all items. Higher scores indicated more violent behaviors (a = 0.79). This measure has shown high reliability and validity and it has been used previously in several published reports.

This is a great questionnaire. The only thing I can think of that’s missing is fighting/arguing with parents.

In regards to testosterone assaying, they were assayed after 11 am to “control for changes due to diurnal rhythm” (Assari, Caldwell, and Zimmerman, 2014). I’m iffy on that since testosterone levels are highest at 8 am but whatever. This analysis is robust. Saliva was not taken if the subject had smoked or ingested something other than water or if a subject was pregnant. Assays should be taken as close to 8 am, as that’s when levels are highest. However one study does argue to extend the range to 8 am to 2 pm (Crawford et al, 2015) while other studies show that this only should be the case for older males (Long, Nguyen, and Stevermer, 2015). Even then assays were done at the higher end of the range as stated by Crawford et al (2015), so differences shouldn’t be too much.

86.4 percent of the sample was black whereas 13.4 percent were white. 41.2 percent of the subjects had some college education whereas 58.2 percent of the subjects lived with a partner or relative. 21.4 percent of the subjects were unemployed.

The mean age was 20.5 for both men and women, however, which will be a surprise to some, testosterone did not predict aggressive behavior in men but did in women. Testosterone and aggressive behavior were positively correlated, whereas there was a negative correlation between education and testosterone and aggressive behavior. Though education was associated with aggressive behavior in men but not women. So sex and education was associated with aggressive behavior (the sex link being women more privy to aggressive behavior while men are more privy to aggressive behavior due to lack of education). Females who had high levels of education had lower levels of aggressive behavior. Again: testosterone wasn’t associated with violent behavior in men, but it was in women. This is a very important point to note.

This was a community sample, so, of course, there were different results when compared to a laboratory setting, which is not surprising. Laboratory settings are obviously unnatural settings whereas the environment you live in every day obviously is more realistic.

This study does contradict others, in that it shows that there is no association between testosterone and aggression in men. However, still other research shows that testosterone is not linked to aggression or impulsivity, but to sensation-seeking, sexual experience or sociality (Daitzman and Zuckerman, 1980; Zuckerman, 1984). Clearly, testosterone is a beneficial hormone and due to the low correlation of testosterone with aggression (between .08 and .14; Book, Starzyk, and Quinsey, 2001; Archer, Graham-Kevan and Davies, 2005; Book and Quinsey, 2005). This paper, yet again, buttresses my arguments in regards to testosterone and aggressive behavior.

In regards to the contrast in the literature the authors describe, they write:

One of the many factors that may explain the inconsistency in these findings is the community versus clinical setting, which has been shown to be a determinant of these associations. Literature has previously shown that many of the findings that can be found in clinical samples may not be easily replicated in a community setting (36).

This is like the (in)famous, unreplicable stereotype threat (see Stroessner and Good). It can only be replicated in a lab, not in an actual educational setting. And it also seems that this is the case for testosterone and aggressive behavior.

Just because women have lower testosterone and are less likely to engage in aggressive behavior, that doesn’t mean that a relationship does not exist between females. “It is also plausible to attribute sex differences in the above studies to differential variations in the amount of testosterone among men and women” (Assari, Caldwell, and Zimmerman, 2014). This view supports the case that testosterone is linked to aggression in females, even though their range of testosterone is significantly lower than men’s, while it may also be easier to assay women for testosterone due to less diurnal variation in comparison to men (Book, Starzyk, and Quinsey, 2001).

Assari, Caldwell, and Zimmerman, (2014) also write (which, again, buttresses my arguments):

Age may explain some of the conflicting results across the studies. A meta-analysis of community and selected samples suggested that there might be only low to modest association between testosterone and aggression, with mean weighted correlations ranging from 0.08 to 0.14, in males. Overall, these meta-analyses suggest that the testosterone-aggression association is equally strong in 12 to 21-year-olds, as it is in 22 to 35-year-olds, but that it may be less strong in age groups younger than 12, than in those who are older.

So, testosterone may be associated with aggressive behavior and violence in women but not in men. In men, the significant moderator was education. It’s interesting to note that Mazur (2016) noted that young black males with little education had higher levels of testosterone than age-matched samples of other blacks. This, along with the evidence provided here, may be a clue that if the social environment changes, then so will higher levels of testosterone (as I have argued here).

They, perhaps taking too large of a leap here, argue that “aggressive behaviors may be more social and less biologically based among men” (Assari, Caldwell, and Zimmerman, 2014). Obviously social factors are easier to change than biological ones (in theory), so, they argue, preventative measures may be easier for men than women. More studies need to be done on the complex interactions between sex, testosterone, aggression, biology and the social environment which then shapes the aggressive behaviors of those who live there.

Testosterone and aggression studies are interesting. However, you must know a good amount of the literature to be able to ascertain good studies from the bad, what researchers should and should not have controlled for, time of assay, etc because these variables (some not in the author’s hands, however) can and do lead to false readings if certain variables are not controlled for. All in all, the literature is clearly points to, though other studies contest this at times, the fact that testosterone does not cause aggressive behavior in men. The myth needs to die; the data is piling up for this point of view and those who believe that testosterone causes aggressive behavior and crime (which I have shown it does not, at least for men) will soon be left in the dust as we get a better understanding of this pivotal hormone.

(In case anyone was going to use this as evidence that black women have higher levels of testosterone than white women, don’t do it because it’s not true. You’ll only embarrass yourself like this guy did. Read the comments and see him say that you don’t need scientific measurements, you only need to ‘observe it’ and through ‘observation’ we can deduce that black women have higher levels of testosterone than white women. This is not true. Quoting Mazur, 2016:

The pattern [high testosterone] is not seen among teenage boys or among females.

…

There is no indication of inordinately high T among young black women with low education.

Whoever still pushes that myth is an idealogue; I have retracted my article ‘Black Women and Testosterone‘, but idealogues just gloss over it and read what they think will bolster their views when I have provided the evidence to the contrary. It pisses me off that people selectively read things then cite my article because they think it will confirm their pre-conceived notions. Well too bad, things don’t work like that.)