<p>There is some truth to this. I don't have the time to go into details but I've found an interesting link..</p>

<p><a href="https://books.google.ch/books?hl=en&amp;lr=&amp;id=5lMP9ivOoxcC&amp;oi=fnd&amp;pg=PA11&amp;dq=environmental+toxins+violence+rate&amp;ots=SKB0rFeBnA&amp;sig=w4g2Ne5JfwT0v36m5gFwPbqJCRw#v=onepage&amp;q=environmental%20toxins%20violence%20rate&amp;f=false" rel="nofollow">https://books.google.ch/books?hl=en&amp;lr=&amp;id=5lMP9ivOoxcC&amp;oi=fnd&amp;pg=PA11&amp;dq=environmental+toxins+violence+rate&amp;ots=SKB0rFeBnA&amp;sig=w4g2Ne5JfwT0v36m5gFwPbqJCRw#v=onepage&amp;q=environmental%20toxins%20violence%20rate&amp;f=false</a></p>

CC BY-SA 3.0
2015-02-16T16:34:34.537Z
2015-02-16T16:34:34.537Z
CuriousIndeed
<p>Saw this: <a href="http://www.motherjones.com/environment/2013/01/lead-crime-link-gasoline" rel="nofollow">http://www.motherjones.com/environment/2013/01/lead-crime-link-gasoline</a></p>

<blockquote>
  <p>Lead emissions from tailpipes rose steadily from the early '40s
  through the early '70s, nearly quadrupling over that period. Then, as
  unleaded gasoline began to replace leaded gasoline, emissions
  plummeted.</p>
  
  <p>Intriguingly, violent crime rates followed the same upside-down U
  pattern... The two curves looked eerily identical, but were <strong>offset
  by about 20 years</strong>.</p>
</blockquote>

<p>They claim a strong methodology: they studied during the phaseout of leaded fuel (which was not implemented uniformly across places, crucially) and subsequent violence levels. The same trend was proved across the world. Lead shrinks the part of the brain responsible for empathy, hence where lead poisoning was more common, people are more predisposed to violence. Big cities thus become more violent.</p>

<p>Do widely-spread brain toxins explain more violence? Are many violent criminals people who got their prefrontal cortexes shrunk by toxins? Do big cities make people aggressive and violent due to increased concentration of toxins?</p>

CC BY-SA 3.0
2013-01-04T21:17:12.440Z
Welcome to CogSci.SE!  A few suggestions: at the end of the question you actually have 3 questions.  I would recommend creating separate questions on CogSci for each.  Remember that we ask you to do some initial research first though!  Speaking of research, have you read the entire Mother Jones article?  Considering the amount of evidence that they have, I would highly doubt that there is any other explanation...
BenCole
CC BY-SA 3.0
2013-01-04T21:41:12.000Z
@BenCole I meant them to be slightly redundant ways. I asked of a trend; big cities are extremes of this trend, and its pertinent to me; hence third question. :-) Second question was to avoid "technically correct" generalizations that can confuse me. Yes I have read it all. And I do want to learn of similar research which is now highly regarded.
Jesvin Jose
CC BY-SA 3.0
2013-01-04T22:16:50.877Z
I understand now.  I'm curious still: do you doubt the research or linked papers in the article?  It seems that the article, or the linked papers, readily answer your first question.  Unfortunately, I suspect there are many reasons for a slightly smaller prefrontal cortex than just toxins and more reasons for violence than a small prefrontal cortex.  Also, considering that *anything* in sufficient quantity can be a toxin, I suspect that the last two questions are too broad for us to be able to answer here.
BenCole
CC BY-SA 3.0
2013-01-05T18:19:51.443Z
I think the important distinction here is "factor in" versus "explain".  Could it be a factor?  Certainly.  However, to say that things like population density *aren't* a larger contributor would be ignoring a lot of already established notions.  I think it's a great question and worth asking, it's just likely to be more complicated, as Ben pointed out.
Chuck Sherrington
CC BY-SA 3.0
2013-01-06T08:11:20.497Z
There's many strong evolutionary arguments for aggression...
Keegan Keplinger
CC BY-SA 3.0
2013-01-06T14:41:25.753Z
I've heard the exact same phenomenon( difference I violence rates) being explained by a completely different thing. What it was escapes me now, but I don't think there is a single simplistic explanation, like lead.
Alex Stone
CC BY-SA 4.0
2021-06-20T18:46:30.150Z
A [meta-analysis](https://www.gla.ac.uk/media/Media_774797_smxx.pdf) came out this year: "We  find  evidence  of  publication  bias across a range of tests. This publication bias means that the effect of lead is overstated in the literature. ... Our results suggest lead does not explain the majority of the large fall in crime observed in some countries, and additional explanations are needed."
Arnon Weinberg
<neuroscience><forensic-psychology>
Do widespread brain toxins explain violence rates?
Jesvin Jose
# Do widespread brain toxins explain violence rates?

(Asked by: username_0 on 2013-01-04)

Saw this: <http://www.motherjones.com/environment/2013/01/lead-crime-link-gasoline>

> Lead emissions from tailpipes rose steadily from the early '40s
> through the early '70s, nearly quadrupling over that period. Then, as
> unleaded gasoline began to replace leaded gasoline, emissions
> plummeted.
>
> Intriguingly, violent crime rates followed the same upside-down U
> pattern... The two curves looked eerily identical, but were **offset
> by about 20 years**.

They claim a strong methodology: they studied during the phaseout of leaded fuel (which was not implemented uniformly across places, crucially) and subsequent violence levels. The same trend was proved across the world. Lead shrinks the part of the brain responsible for empathy, hence where lead poisoning was more common, people are more predisposed to violence. Big cities thus become more violent.

Do widely-spread brain toxins explain more violence? Are many violent criminals people who got their prefrontal cortexes shrunk by toxins? Do big cities make people aggressive and violent due to increased concentration of toxins?

**Tags:** neuroscience, forensic-psychology

> **Comments:**
> **username_1**: Welcome to CogSci.SE!  A few suggestions: at the end of the question you actually have 3 questions.  I would recommend creating separate questions on CogSci for each.  Remember that we ask you to do some initial research first though!  Speaking of research, have you read the entire Mother Jones article?  Considering the amount of evidence that they have, I would highly doubt that there is any other explanation...  
> **username_0**: @username_1 I meant them to be slightly redundant ways. I asked of a trend; big cities are extremes of this trend, and its pertinent to me; hence third question. :-) Second question was to avoid "technically correct" generalizations that can confuse me. Yes I have read it all. And I do want to learn of similar research which is now highly regarded.  
> **username_1**: I understand now.  I'm curious still: do you doubt the research or linked papers in the article?  It seems that the article, or the linked papers, readily answer your first question.  Unfortunately, I suspect there are many reasons for a slightly smaller prefrontal cortex than just toxins and more reasons for violence than a small prefrontal cortex.  Also, considering that *anything* in sufficient quantity can be a toxin, I suspect that the last two questions are too broad for us to be able to answer here.  
> **username_2**: I think the important distinction here is "factor in" versus "explain".  Could it be a factor?  Certainly.  However, to say that things like population density *aren't* a larger contributor would be ignoring a lot of already established notions.  I think it's a great question and worth asking, it's just likely to be more complicated, as Ben pointed out.  
> **username_3**: There's many strong evolutionary arguments for aggression...  
> **username_4**: I've heard the exact same phenomenon( difference I violence rates) being explained by a completely different thing. What it was escapes me now, but I don't think there is a single simplistic explanation, like lead.  
> **username_5**: A [meta-analysis](https://www.gla.ac.uk/media/Media_774797_smxx.pdf) came out this year: "We  find  evidence  of  publication  bias across a range of tests. This publication bias means that the effect of lead is overstated in the literature. ... Our results suggest lead does not explain the majority of the large fall in crime observed in some countries, and additional explanations are needed."  

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## 1 answers

### Answer by username_6 on 2015-02-16. Score: 1

There is some truth to this. I don't have the time to go into details but I've found an interesting link..

<https://books.google.ch/books?hl=en&lr=&id=5lMP9ivOoxcC&oi=fnd&pg=PA11&dq=environmental+toxins+violence+rate&ots=SKB0rFeBnA&sig=w4g2Ne5JfwT0v36m5gFwPbqJCRw#v=onepage&q=environmental%20toxins%20violence%20rate&f=false>


---

