Read on Twitter
THREAD: Sex Differences in Aggression
According to a recent New York Times piece, boys are more violent than girls – but their tendency to violence isn& #39;t innate. https://www.nytimes.com/2019/03/30/opinion/sunday/boys-men-violence.html
Certainly,">https://www.nytimes.com/2019/03/3... socialization matters. But biology matters as well. Here& #39;s how we know... 1/10
According to a recent New York Times piece, boys are more violent than girls – but their tendency to violence isn& #39;t innate. https://www.nytimes.com/2019/03/30/opinion/sunday/boys-men-violence.html
Certainly,">https://www.nytimes.com/2019/03/3... socialization matters. But biology matters as well. Here& #39;s how we know... 1/10
First, "we spend a lot more time discouraging male aggression than female… Males, it seems, are more aggressive *despite* culture, not because of it." https://www.amazon.com/Ape-that-Understood-Universe-Culture/dp/1108732755/">https://www.amazon.com/Ape-that-... #TheApeThatUnderstoodTheUniverse 2/10
"By clamping down on male aggression, culture may sometimes make the sex difference in aggression *smaller* than it would otherwise have been." https://www.amazon.com/Ape-that-Understood-Universe-Culture/dp/1108732755/">https://www.amazon.com/Ape-that-... #TheApeThatUnderstoodTheUniverse 3/10
Second, "the sex difference in aggression appears very early in life… [and] remains static until puberty… If socialization creates the sex difference, why doesn& #39;t continued socialization before puberty pry the sexes apart?" https://www.amazon.com/Ape-that-Understood-Universe-Culture/dp/1108732755/">https://www.amazon.com/Ape-that-... 4/10
![Second, "the sex difference in aggression appears very early in life… [and] remains static until puberty… If socialization creates the sex difference, why doesn& #39;t continued socialization before puberty pry the sexes apart?" https://www.amazon.com/Ape-that-... 4/10](https://pbs.twimg.com/media/ELsrzOJUEAA0LDA.jpg "Second, \"the sex difference in aggression appears very early in life… [and] remains static until puberty… If socialization creates the sex difference, why doesn& #39;t continued socialization before puberty pry the sexes apart?\" https://www.amazon.com/Ape-that-... 4/10")
![Second, "the sex difference in aggression appears very early in life… [and] remains static until puberty… If socialization creates the sex difference, why doesn& #39;t continued socialization before puberty pry the sexes apart?" https://www.amazon.com/Ape-that-... 4/10](https://pbs.twimg.com/media/ELsrzOJVAAEysd0.jpg "Second, \"the sex difference in aggression appears very early in life… [and] remains static until puberty… If socialization creates the sex difference, why doesn& #39;t continued socialization before puberty pry the sexes apart?\" https://www.amazon.com/Ape-that-... 4/10")
Third, "as with many sex differences, the sex difference in aggression suddenly swells at puberty… Is it just a coincidence that this comes at the same time as the massive surge in circulating testosterone that accompanies puberty in males?" https://www.amazon.com/Ape-that-Understood-Universe-Culture/dp/1108732755/">https://www.amazon.com/Ape-that-... 5/10
Fourth, "male aggression steadily nosedives through the remainder of the lifespan. The socialization hypothesis offers no particular reason to expect this." https://www.amazon.com/Ape-that-Understood-Universe-Culture/dp/1108732755/">https://www.amazon.com/Ape-that-... #TheApeThatUnderstoodTheUniverse 6/10
Fifth, sex differences in aggression are a cross-cultural universal. In every culture on record, for instance, men commit the vast majority of homicides (and are more likely to be the victims of homicide as well). http://www.unodc.org/documents/gsh/pdfs/2014_GLOBAL_HOMICIDE_BOOK_web.pdf">https://www.unodc.org/documents... http://nautil.us/blog/nurture-alone-cant-explain-male-aggression">https://nautil.us/blog/nurt... 7/10
Sixth, contrary to the idea that sex differences are a product of gender roles, sex differences in adolescent physical aggression are larger, not smaller, in more gender-equal nations (N = 247,909) https://onlinelibrary.wiley.com/doi/epdf/10.1002/ab.21799">https://onlinelibrary.wiley.com/doi/epdf/... http://nautil.us/blog/nurture-alone-cant-explain-male-aggression">https://nautil.us/blog/nurt... 8/10
Finally, comparable differences are found in many other species. For example…
Humans: Males commit 95% of homicides and are 79% of homicide victims http://www.unodc.org/documents/gsh/pdfs/2014_GLOBAL_HOMICIDE_BOOK_web.pdf
Chimps:">https://www.unodc.org/documents... Males commit 92% of chimpicides and are 73% of chimpicide victims https://www.nature.com/articles/nature13727">https://www.nature.com/articles/... 9/10
Humans: Males commit 95% of homicides and are 79% of homicide victims http://www.unodc.org/documents/gsh/pdfs/2014_GLOBAL_HOMICIDE_BOOK_web.pdf
Chimps:">https://www.unodc.org/documents... Males commit 92% of chimpicides and are 73% of chimpicide victims https://www.nature.com/articles/nature13727">https://www.nature.com/articles/... 9/10
For more on the origins of human sex differences, check out Chapter 3 of my book The Ape That Understood the Universe – featuring a new foreword by the inimitable @MichaelShermer! 
https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index"> https://www.amazon.com/Ape-that-Understood-Universe-Culture/dp/1108732755/">https://www.amazon.com/Ape-that-... 10/10
https://www.amazon.com/Ape-that-... 10/10" title="For more on the origins of human sex differences, check out Chapter 3 of my book The Ape That Understood the Universe – featuring a new foreword by the inimitable @MichaelShermer! https://abs.twimg.com/emoji/v2/... draggable="false" alt="👇" title="Down pointing backhand index" aria-label="Emoji: Down pointing backhand index"> https://www.amazon.com/Ape-that-... 10/10" class="img-responsive" style="max-width:100%;"/>
