They have #Statistics to show the #Correlation, they have #Hypothesis to connect plausible & likely functional relationships between the cause and the effect. As a parent, I've heard a lot of things over the years claiming to adjust the likelihood of a child's gender through food or other silliness, but this is the first one I heard that made sense. I could be wrong, but it seems that—for example—if prospective #dads want #sons they should go to great lengths to not be an #Asshole and to woo their partner. If #parents want #daughters, they will have to try to walk that dangerous tightrope of #stress that could lead to failed attempts to #conceive.
If you want to get right to the audio highlight, slide the cue handle to about 21:34.