I attended TEDx Berkeley 2013 today and it was my first TED type event. I was largely unimpressed by the talks and felt somewhat isolated in the sea of twenty-somethings that attended the Zellerbach Hall event on the UC Berkeley campus. Nonetheless, I will try to share some shards worthy of interest.
The event was divided into three programs entitled Dream, Create, and Impact. Being a night person, of course I missed the entire Dream section which occurred from 10:00 – 11:30 am.
Louann Brizandine, author of the Female Brain, was the first speaker that I was able to see. Her basic thesis being that men’s and women’s brains differ biologically, largely due to hormonal influences. She gave a folksy presentation light on facts. Better writers than I have beaten up on her previous work for this tendency. She referred to babies as “marinating” in hormones and included a photo of a large breasted woman in her slides to grab the attention of straight men (and presumably some gay women?). She indulged in what I like to call “evolutionarily adaptive storytelling” by telling the audience that evolution has shaped men to be attracted to large breasted females since large breasts are a signal of high estrogen levels and thus fertility.
I don’t mind this sort of storytelling, but it’s more interesting if some empirical evidence is shown. This particular story suggests that smaller breast sizes would be evolutionarily maladaptive, and it’s not clear that this is true. Of course, these stories certainly oversimplify evolution. Intuitively, it has long seemed to me that nonadaptive but neutral traits should survive in populations as long as they aren’t specifically maladaptive. Organisms that maintain a variety of these neutral traits would appear to be more robust since a neutral trait for one environment might turn out to be life-saving under changed circumstances. Setting my own confirmation bias aside, I have found some evidence to suggest that evolution is less driven by adaptation than some may think.
But I am digging deeper than Brizandine delved during her talk. She went on to touch on the differences between how boys and girls like to play. Here she did cite Eleanor Maccoby’s work which suggests that socialization has a limited impact on gender roles. Brizandine described girl play as being relational in nature while boys prefer rough physical play. She suggested that brain circuits are powered by hormones, and cited the anecdotal story of a transgendered person going from female to male who experienced a drop in tolerance for converstations with his female friends. This example makes her arguments more palatable to me. Determinist though I am, I get annoyed by arguments biased toward nature in nature vs nurture discussions. I am attracted to theories of behavior that allow for change and allow for agency. I like the idea that a biological woman that really, really, wanted to think more like a man could take hormones and achieve some aspect of that. That’s why epigenetics is also fascinating to me. Give me the wisdom to know what I can change…
Read Part 2 of my TEDx Berkeley 2013 coverage here.
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I’ve always found that just-so stories about evolutionary adaptation are excellent thought experiments, even in the absence of empirical data.
In the example of evolution shaping men to be attracted to large breasted females, this might be adaptive even as small breasts are not maladaptive. If there is a cost to the adaptive feature, then there will be a tradeoff. A similar example is bilateral symmetry. Both men and women apparently find it attractive, but it is only one factor among many, and if it is absent there are still many other facets to consider.
Sexual divergence due to evolution is a bit of a minefield, but it seems likely that there’s something there, doesn’t it?