The Breeder's Equation
The author is playing fast and loose with definitions here. Other sources[0][1] (that I would consider more reputable) define the breeder&#x27;s equation in terms of populations, but this author focuses on arbitrary and ill-defined subsets of populations.<p>Crucially, the author defines R as &quot;the response to selection&quot;, but he omits the second part: &quot;from one generation to the next&quot;. Source [0] defines it even more clearly: &quot;the change in the mean [of the population] over one complete generation&quot;.<p>Similarly, S is the difference in the measured trait among the entire population and the population that reproduces. So when the author considers &quot;a set of parents with IQs of 120&quot;, it only fits the correct usage of the equation if we take that to mean that mean IQ of all parents in this generation is 120. If that&#x27;s his argument, how is he defining the population of parents?<p>In my opinion, this is a wishy-washy argument that seems like a subtle way of advancing eugenics (or something similarly distasteful).<p>[0]: <a href="https:&#x2F;&#x2F;www.nature.com&#x2F;scitable&#x2F;knowledge&#x2F;library&#x2F;the-breeder-s-equation-24204828&#x2F;" rel="nofollow">https:&#x2F;&#x2F;www.nature.com&#x2F;scitable&#x2F;knowledge&#x2F;library&#x2F;the-breede...</a>
[1]: <a href="https:&#x2F;&#x2F;public.wsu.edu&#x2F;~gomulki&#x2F;biol519&#x2F;presentations&#x2F;SjobergStraussLarkinPSS.pdf" rel="nofollow">https:&#x2F;&#x2F;public.wsu.edu&#x2F;~gomulki&#x2F;biol519&#x2F;presentations&#x2F;Sjober...</a>