So I want to point out something for a bit, call me butthurt if you will but this really irked me while I was reading. Author got the research wrong. First off, it's not a blanket 50% of your personality in your genetics, secondly even in that we find a lot of variation between genetics and personality traits.
"Scientists estimate that 20 to 60 percent of temperament is determined by genetics. Temperament, however, does not have a clear pattern of inheritance and there are not specific genes that confer specific temperamental traits. Instead, many (perhaps thousands) of common gene variations (polymorphisms) combine to influence individual characteristics of temperament. Other DNA modifications that do not alter DNA sequences (epigenetic changes) also likely contribute to temperament."
The author is also literally contradicting the research by saying home environment doesn't play a large roll.
"Environmental factors also play a role in temperament by influencing gene activity. In children raised in an adverse environment (such as one of child abuse and violence), genes that increase the risk of impulsive temperamental characteristics may be turned on (activated). However, a child who grows up in a positive environment (for example a safe and loving home) may have a calmer temperament, in part because a different set of genes is activated"
I get the author is trying something, because he used the daughter as an example of someone who ISN'T the same as her dad to act as a counter to the argument (if this is completely true then she should be a bully too), but he still shouldn't skew data for a plot point.