The so-called "Cinderella effect" - which states that it is biologically inevitable that parents care less for stepchildren because they do not spread their genes - may not be true all the time, claim researchers. me.
The study found that if there is a reasonable chance of increasing wealth in the parents' environment then no difference is made between one's own children and stepchildren.
Max Planck Institute for Demographic Research researcher Kai Willfuhr said that they are now able to prove that the Cinderella effect is not an inevitable reflex of stepparents.
They compared the Krummhorn region of East Frisia (Germany), which was a densely populated area with little space for demographic development, and the growing Canadian settlements in Quebec.
For both areas they calculated how the children's chances of survival changed when a stepmother moved in.
The conclusions showed that only in Krummhorn, which offered fewer opportunities for demographic growth, the stepmother had a negative influence.
In Krummhorn children from a father's first marriage died more often before the age of 15 if a stepmother moved in.
This effect was not seen in Quebec, even though the tragedy of Aurore Gagnon, a young girl who died from wounds inflicted by her stepmother and her father in 1920, is still fresh in Quebec's collective memory .
The "Cinderella effect," therefore, does not inevitably seem to occur. The stepmothers must have treated their children in East Frisia and Canada completely differently.
The study has been published in scientific journal Biodemography and Social Biology.