Einige Studien zu Vätern:
Despite the widespread assumption that paternal investment is substantial in our species, previous studies have shown mixed results in relation to the impact of fathers on both offspring survival and reproductive outcomes. Using data from a large representative sample of British men, we tested whether father absence is associated with the timing of reproduction-related events among boys, while controlling for various cues denoting early childhood adversity. We further tested whether the loss of the father at different childhood stages matters, so as to assess whether early life is the most important period or if effects can be seen during later childhood. The results show that father absence before age seven is associated with early reproduction, while father absence between ages 11 and 16 only is associated with delayed voice-breaking (a proxy for puberty), even after adjusting for other factors denoting childhood adversity. We conclude that fathers do exert an influence on male reproductive outcomes, independently of other childhood adversities and that these effects are sensitive to the timing of father absence.
Kinder, deren Vater im Alter bis 7 Jahren nicht anwesend waren, bekommen also früher Kinder, fehlt der Vater zwischen 11-16 Jahren verzögert sich die Pubertät.
Eine weitere Studie scheint einen größeren Einfluss der Vaterschaft festgestellt zu haben:
This article explores the cultural construction of fatherhood in America, as well as the consequences of this construction as a motivator for understudying fathers—especially father love—for nearly a century in developmental and family research. It then reviews evidence from 6 categories of empirical studies showing the powerful influence of fathers‘ love on children’s and young adults‘ social, emotional, and cognitive development and functioning. Much of this evidence suggests that the influence of father love on offspring’s development is as great as and occasionally greater than the influence of mother love. Some studies conclude that father love is the sole significant predictor of specific outcomes after controlling for the influence of mother love. Overall, father love appears to be as heavily implicated as mother love in offsprings‘ psychological well-being and health, as well as in an array of psychological and behavioral problems
Andere Studien kommen zu weniger klaren Ergebnissen:
Children pose a problem. The extended period of childhood dependency and short interbirth intervals mean that human mothers have to care for several dependent children simultaneously. Most evolutionary anthropologists now agree that this is too much of an energetic burden for mothers to manage alone and that they must enlist help from other relatives to share the costs of raising children. Which kin help is the subject of much debate. Here, we review the evidence for whether the presence of kin affects child survival rates, in order to infer whether mothers do receive help in raising offspring and who provides this help. These 45 studies come from a variety of (mostly) natural fertility populations, both historical and contemporary, across a wide geographical range. We find that in almost all studies, at least one relative (apart from the mother) does improve the survival rates of children but that relatives differ in whether they are consistently beneficial to children or not. Maternal grandmothers tend to improve child survival rates as do potential sibling helpers at the nest (though the latter observation is based on rather few studies). Paternal grandmothers show somewhat more variation in their effects on child survival. Fathers have surprisingly little effect on child survival, with only a third of studies showing any beneficial effects. Overall, this review suggests that whilst help from kin may be a universal feature of human child-rearing, who helps is dependent on ecological conditions.
Dabei geht es also um das pure Überleben, bei dem der Vater nur in einem bestimmten Teil der Studien einen Einfluss hatte. Es wäre zu vermuten, dass der Einfluss insbesondere bei schlechten Bedingungen hoch ist. Allerdings ist überleben nicht das einzige Kriterium:
This study used data from the Panel Study of Income Dynamics and its 1997 Child Development Supplement to examine how family income matters for young children’s development. The sample included 753 children who were between ages 3 and 5 years in 1997. Two sets of mediating factors were examined that reflect two dominating views in the literature: (1) the investment perspective, and (2) the family process perspective. The study examined how two measures of income (stability and level) were associated with preschool children’s developmental outcomes (Woodcock-Johnson [W-J] Achievement Test scores and the Behavior Problem Index [BPI]) through investment and family process pathways. Results supported the hypothesis that distinct mediating mechanisms operate on the association between income and different child outcomes. Much of the association between income and children’s W-J scores was mediated by the family’s ability to invest in providing a stimulating learning environment. In contrast, family income was associated with children’s BPI scores primarily through maternal emotional distress and parenting practices. Level of income was associated with W-J letter-word scores and income stability was associated with W-J applied problem scores and BPI, even after all controls were included in the models.
Hier ist zwar zunächst nur von dem Familieneinkommen die Rede, dass natürlich auch die Frau als Hauptverdiener erwirtschaften kann. Allerdings ist dies in der Praxis eben meist der Vater. Ein hohes Einkommen erhöht dabei die Möglichkeiten für das Kind sich auf das Lernen zu konzentrieren und bietet eine gute Lernumgebung und erlaubt zudem der Mutter (oder dem Vater, wenn er die Kinder versorgt) entspannter zu sein. Das es bei dem Gesichtspunkt eines guten Versorgers nicht nur um das schlichte Überleben gehen muss, sondern auch darum, dass die Kinder sich optimal entwickeln ist ein weiterer Grund dafür, dass ein evolutionärer Druck entstanden sein könnte, gute Versorger attraktiv zu finden.
Auch Stiefväter bzw. neue Partner können als Versorger interessant sein:
We present a biosocial model of human male parental care that allows male parental allocations to be influenced not only by changes in the fitness (welfare) of the recipient offspring, but also by their effects on the man’s relationship with the child’s mother. The model recognizes four classes of relationships between males and the children they parent: genetic offspring of current mates (combined relationship and parental effort), genetic offspring of previous mates (parental effort solely), step offspring of current mates (relationship effort solely), and stepchildren of previous mates (essentially no expected investment). We test the model using data on parental investments collected from adult males living in Albuquerque, New Mexico, U.S.A. Four measures of paternal investment are examined: the probability that a child attends college (2,191 offspring), the probability that a child who attends college receives money for it (N = 1,212), current financial expenditures on children (N = 635), and the amount of time per week that men spend with children ages 5 to 12 years (N = 2,589). The tests are consistent with a role for relationship effort in parental care: men invest more in the children of their current mates, even when coresidence with offspring is not a confounder.
Das Unterstützen von Kindern aus „erster Ehe“ wäre dann biologisch betrachtet Werbeverhalten gegenüber der Mutter, aber gerade das würde sowohl Großzügigkeit des Mannes als auch eine diesbezügliche Vorliebe der Frauen für solches Verhalten biologisch interessant machen.
Zudem hat der soziale Status auch einen erheblichen Einfluss auf die Gesundheit:
Socio-economic status (SES) has a major impact on health (WHO, 2002; Adams & White, 2004; Marmot, 2004, 2005; Sapolsky, 2005). There is a wealth of evidence that lower SES is associated with increased risks of cardiovascular, respiratory, rheumatic and psychiatric diseases; low birthweight; infant mortality; and mortality from all causes (Sapolsky, 2005).
Mit Hilfe eines Mannes dürfte in den meisten Gesellschaften ein höherer socio-economischer Status zu erreichen sein, so dass damit für die Kinder und die Mutter diese Risiken verringert werden.