Scientific Blackpill: Difference between revisions

A study in 2013 examining a total of 2.3 million individuals born in Sweden in 1950-1970, using government health care records, found evidence for substantially lower fertility among sufferers of various mental illnesses. The fertility of the mentally ill was computed by measuring the fertility ratio (e.g. a FR of .5 would mean that the diseased group had on average half of the children of the general non-affected population, a FR of 2 would mean double the offspring on average) which reflected the mean number of children that individuals with various mental disorders had, as compared to control individuals of the same age and sex, also accounting for variables such as family size, affected status and parental status.  The youngest individuals involved, at the time their data was recorded, were 40 years old, and had thus likely largely completed their [[reproductive success|reproductive careers]].

The researchers found evidence of substantially strong selection pressure against schizophrenia (male FR .23 vs female FR .47) , autism (male FR .25 vs female FR .48), and anorexia nervosa (male FR .54 vs female FR .81), but not bi-polar disorder.  Depression was weakly negatively associated with fertility for men (FR .93) and not at all for women, and substance abuse disorders was also negatively associated with fertility for men, with a weaker relationship with fertility and the condition being discovered for women (male FR .78 vs female FR .92) It was also found that the selection pressure against these disorders was found to be consistently higher much among men who suffered from them, as compared to the women who suffered from these conditions. This is in accordance with [[Bateman's principle]], which suggests that males of most animal species have greater reproductive variance than females.

The researchers also found evidence that the fertility of siblings of those with mental disorders was generally lower also, with it also being found that the fertility of the male siblings of those with certain mental disorders was also generally lower than their female siblings, similar to the relationship that was discovered regarding the differential effects of mental illness on fertility being moderated by sex.  

However, there was also evidence that siblings of those that suffered from depression had a larger number of children on average, indicating that balancing selection was therefore operating on genes associated with propensity to depression, i.e. the fertility cost to the sufferers of the condition is potentially balanced out by the increased fecundity of their siblings. The researchers also discovered a similar relationship regarding substance abuse disorders also being associated with balancing selection, likely due to the association of this condition with genes likely involved in greater risk tasking propensity, which have also been shown to be generally related to greater sexual success.

The researchers concluded that schizophrenia and autism were therefore under purifying selection (being "bred out", basically) in modern Western societies, with the continuing high prevalence of these conditions, possibly being maintained through new mutations (possibly due to increased paternal age). The researchers stated that it has been been supported by prior research (MacCabe et al., 2009), that the sufferers of these conditions lower fertility is likely largely due to the those that have these mental conditions being less able to find a partner to marry/have children with, and this dynamic is stronger among males who suffer from mental illness, as compared to female sufferers.

There is [https://www.theguardian.com/society/2018/sep/14/thousands-of-autistic-girls-and-women-going-undiagnosed-due-to-gender-bias evidence] that many autistic women go underdiagnosed, which presumably mainly affects women with a relatively mild autism such that they have higher reproductive success. This should imply that overall autistic women may have an ''even'' higher reproductive success than autistic men. Autism is hence much more propagated in the gene pool by women than by men. Further, it could mean that [[Females are socially inept| women, not men are overall more autistic]], but that it goes unnoticed because less is expected of women, and men's standards are lower. An awkward woman may also be perceived as [[neoteny|neotenous]] by men as awkwardness is a childish trait, but neoteny is sexually attractive to men as men like to monopolize women at child age to [[paternity assurance|ensure paternity]]. Socially awkward women may also seem like particularly "easy prey" for men ([[Juggernaut law]]).

*  ''Except for women with depression, affected patients had significantly fewer children (FR range for those with psychiatric disorder, 0.23-0.93; P < 10−10). This reduction was consistently greater among men than women, suggesting that male fitness was particularly sensitive.''

* ''Depression and, to a lesser extent, substance abuse, seems to be maintained by genes that are beneficial under some circumstances (ie, in siblings) but detrimental in others (i.e, affected individuals).''