Q. I am a polygamist with several wives and many children. All of my children, except my eldest, are very pro-polygamy. My first wife was always very hostile to polygamy, and still is (we were divorced many years ago). My eldest daughter, in spite of being raised in a polygamous household and being treated like all the other children, still hates polygamy. Do you think this is a genetic disposition she has inherited from her mother?
This is without doubt a very difficult question to answer because I don't think we can ever be sure. As I have argued elsewhere, I believe that being for or against polygamy is very much a personal choice based on circumstances. The fact that you and your first wife are divorced may play a greater part in your daughter's orientation than you think - she may unconsciously side with her anti-polygamous mother not because her mother was against polygamy but because she sides with her mother over the divorce issue, and not because of her mother's anti-polygamy stance per se. In other words, because she sympathised with her mother's reasons for divorce, she may have simply just adopted her whole way of being too. So I think the issue may well be a behaviouristic one.
On the other hand, I have met numerous people who agree that polygamy is scriptural but who consistenly argue that the lifestyle simply does not gel with their nature, and may at times play the 'genetic card'. In my own opinion, this is no different from a homosexual blaming his genes for his homosexuality, or an alcoholic doing the same thing. There is a great deal of controversial research claiming that these characteristics are inheritable though personally I am sceptical.
This brings us into another area of controversy, namely, whether behavioural characteristics can be learned and inherited genetically. Lamarck, the Swedish biologist, seemed to think so, though his view was always a minority one in the scientific establishment. Personally I think such characteristics can be inheritable, though whether it is effected through the genetic material or through some other mechanism, I cannot say. If it is inheritable, then I believe it can be modified by subsequent behavioural changes caused by the choice to work with, and overcome, certain negative dispositions. I certainly do not believe that if we have a negative behavioural disposition or sexual preference that we are the victims of immutable genetics - if I did believe that, then all of the examples of homosexuals becoming normal heterosexuals would have to be dismissed as scientifically impossible. And yet this happens all the time.
The Bible teaches that the sins of the fathers are passed down through several generations, indicating that behaviourism is inheritable. But at the same time I know from personal experience as a minister that such sins can be broken through the blood of Christ. For example, some people find themselves irresistably drawn towards witchcraft and the occult because their ancestors were deeply involved in it. There is no doubt that very often such things 'run in the family', such as the tendency to commit suicide, to get divorced, etc.. But these 'curses' can be broken, and are broken through the atonement of Christ.
So, yes, I do have to say that I am Lamarckian, and I do believe absolutely that inherited dispositions can be broken if the one inheriting these characteristics wants to break them. Because I believe the monogamy-only mindset is an unnatural psychological disposition like homosexuality, I also believe it can be broken through the blood of Christ. But that is really very much up to the individual - if he wants to retain the mindset, then he will.
 Rachel Feltman, Speaking of Science: The Evidence of Polygamy is in Our Genes (25 September 2014)