But a certain mind-set views biology as absolutely determinist of what we are, or can be. To these, we can never be anything more than our animal nature. In its extreme form, it seems no role for women outside of men: Kinder, Kirche, Küche. It seeks a hierarchy of people in which the ultimate is the straight white male Christian-of-a-certain-sort. In the WaPo, Susan Brooks Thistlewaite writes:
A rigid biological determinism undergirds conservative ideology and politics. From this extraordinarily revealing remark by [Jeb] Bush that immigration reform should be about the (presumed) fertility of certain groups over others, to women’s rights, to reproductive freedom, and, of course, to marriage equality for LGBT people, biology for conservatives is, in fact, destiny....
Conservative ideology... based as it is in biological determinism, is designed that way to consolidate and perpetuate the political, social and religious power of small group of elites defined by their biology in terms of gender, sexual orientation and, in the U.S., by race. It uses presumed biological differences to advance and maintain political and economic power, and it has for a very long time.
This interpretation of biology as destiny is designed to preserve the status quo and prevent reform.
To conservatives of this ilk, women can't think as well as men, therefore don't belong in "men's professions". It's why women in science are few in number and underpaid relative to men, facing glass ceilings in careers, awards, and compensation even today.
It's also why the incoherent argument against marriage equality centers on procreation, which on the face of it is ludicrous. Fecundity is not a requirement for heterosexual unions, and moreover, marriage equality is not related to adoption by LGBT couples which is on-going. Not to mention that many LGBT couples are raising their own biological children.
Thistlewaite goes on,
Democracy, by contrast, is based on the idea that human beings are not determined by biology, but “endowed by their Creator with certain unalienable rights.” This is both a political and a religious argument for a profound and transcendent equality governed by rights. As human beings, we have rights that cannot be reduced or eliminated regardless of our individual physical characteristics. Every advance in human rights in this country, from ending slavery, to extending voting rights, to the Civil Rights struggles, to reproductive freedom, and now to the struggle for full equality for LGBT people, equal justice, not biology, has been the crucial argument....
Biology is not our human destiny, freedom is.