Editing Nature versus nurture (section)

== Genetics ==

The relationship between personality and people's own well-being is influenced and mediated by genes.<ref name=Weiss2008 /> There has been found to be a stable set point for happiness that is characteristic of the individual (largely determined by the individual's genes). Happiness fluctuates around that setpoint (again, genetically determined) based on whether good things or bad things are happening to us ("nurture"), but only fluctuates in small magnitude in a normal human. The midpoint of these fluctuations is determined by the "great genetic lottery" that people are born with, which leads them{{Who|date=October 2022}} to conclude that how happy they may feel at the moment or over time is simply due to the luck of the draw, or gene. This fluctuation was also not due to educational attainment, which only accounted for less than 2% of the variance in well-being for women, and less than 1% of the variance for men.<ref name=lykken1996/>

They{{Who|date=October 2022}} consider that the individualities measured together with personality tests remain steady throughout an individual's lifespan. They further believe that human beings may refine their forms or personality but can never change them entirely. Darwin's Theory of Evolution steered naturalists such as George Williams and William Hamilton to the concept of personality evolution. They suggested that physical organs and also personality is a product of natural selection.<ref>{{cite book|first1=Norbert|last1=Herschkowitz|first2=Elinore Chapman|last2=Herschkowitz|title=A Good Start In Life|url=https://archive.org/details/goodstartinlifeu0000hers|url-access=registration|date=2002|publisher=Joseph Henry Press|isbn=9780309076395|edition=2nd}}</ref>

With the advent of [[genomic sequencing|gene sequencing]], it has become possible to search for and identify specific gene polymorphisms that affect traits such as IQ and personality. These techniques work by tracking the association of differences in a trait of interest with differences in specific molecular markers or functional variants. An example of a visible human trait for which the precise genetic basis of differences are relatively well known is [[eye color]].

In contrast to views developed in 1960s that gender identity is primarily learned (which led to a protocol of surgical sex changes in male infants with injured or malformed genitals, such as [[David Reimer]]), genomics has provided solid evidence that both sex and gender identities are primarily influenced by genes:

{{Blockquote|text=It is now clear that genes are vastly more influential than virtually any other force in shaping sex identity and gender identity ... The growing consensus in medicine is that ... children should be assigned to their chromosomal (i.e., genetic) sex regardless of anatomical variations and differences—with the option of switching, if desired, later in life.|sign=[[Siddhartha Mukherjee]]|source=|title=''The Gene: An Intimate History'', 2016}}