Well, the brain does a lot of impressive things :-) We shouldn’t be less impressed by any one impressive thing just because there are many other impressive things too.
Anyway I wrote this blog post last year where I went through a list of universal human behaviors and tried to think about how they could work. I’ve learned more since writing that, and I think I got some of the explanations wrong, but it’s still a good starting point.
What about sexual attraction?
Without getting into too much detail, I would say that sexual attraction involves the same “supervised learning” mechanism I talked about here, but with one extra complication: For salt, it’s trivial to get ground truth about whether you are tasting salt—you have salt taste buds sending their signals straight into the brain, it’s crystal clear. But for sexual attraction, you need an extra computational step to get (approximate) ground truth about whether or not you are interacting with a sexually-attractive (to you) person. (Then that approximate ground truth can be the supervisory signal of the supervised learning algorithm.)
So, where does the “ground truth” for “I am interacting with a sexually-attractive (to me) person” come from? First, I think there are hardwired sight cues, sound cues, smell cues, touch cues, etc. See here for details, particularly my claim that these cues are detected by circuitry in the subcortical sensory processing systems (especially the tectum), not in the neocortex. Second, I’m big into empathetic simulation and think they’re central to all social emotions, and I think that it plays a role in all aspects of sexual attraction too, both physical and emotional. That’s a bit of a long story, I think.
I think newborns finding their mother’s nipple are just going by hardwired smell and touch cues, and hardwired movement routines, I presume in the brainstem. Hardwired stimulus-response, nothing complicated! Well, I don’t really know, I’m just guessing.
Well, the brain does a lot of impressive things :-) We shouldn’t be less impressed by any one impressive thing just because there are many other impressive things too.
Anyway I wrote this blog post last year where I went through a list of universal human behaviors and tried to think about how they could work. I’ve learned more since writing that, and I think I got some of the explanations wrong, but it’s still a good starting point.
What about sexual attraction?
Without getting into too much detail, I would say that sexual attraction involves the same “supervised learning” mechanism I talked about here, but with one extra complication: For salt, it’s trivial to get ground truth about whether you are tasting salt—you have salt taste buds sending their signals straight into the brain, it’s crystal clear. But for sexual attraction, you need an extra computational step to get (approximate) ground truth about whether or not you are interacting with a sexually-attractive (to you) person. (Then that approximate ground truth can be the supervisory signal of the supervised learning algorithm.)
So, where does the “ground truth” for “I am interacting with a sexually-attractive (to me) person” come from? First, I think there are hardwired sight cues, sound cues, smell cues, touch cues, etc. See here for details, particularly my claim that these cues are detected by circuitry in the subcortical sensory processing systems (especially the tectum), not in the neocortex. Second, I’m big into empathetic simulation and think they’re central to all social emotions, and I think that it plays a role in all aspects of sexual attraction too, both physical and emotional. That’s a bit of a long story, I think.
I think newborns finding their mother’s nipple are just going by hardwired smell and touch cues, and hardwired movement routines, I presume in the brainstem. Hardwired stimulus-response, nothing complicated! Well, I don’t really know, I’m just guessing.