The never ending battle for attention between same-sex siblings can be exhausting when you’re young but generally during adulthood, siblings bond and often become the best of friends. However, new research by the University of Sheffield has revealed that the more same-sex siblings you have in young adulthood, the less likely you are to marry and have children.
By Chloe Schneider
The study, which was carried out by experts from the University’s Department of Animal and Plant Sciences by analysing church records of about 20,000 Finnish people born between 1750 and 1900, was carried out to examine the effects of sibling interactions at different life stages.
It showed that each living same-sex sibling decreased the probability of ever having children so that, on average, men with no elder brothers had five children whereas men with elder brothers only had four children.
“Elder siblings have a key role in the family and understanding their effect is pivitol to understanding the evolution of the human family,” said principal investigator Aida Nïtsch. Project leader Dr Virpi Lummaa suggests that this phenomenon could be the result of being in the same social circle saying, “At least in the historical context, in young adulthood, the more same sex siblings you had alive, the less likely you were going to marry, and less children you raised yourself, suggesting that in adulthood it was actually a nuisance, probably because they competed over the same inheritance and marriage prospects.”
The study also showed that during childhood, a boy with no elder siblings had only on average a 68 per cent chance of surviving to age 15, whereas a boy with four elder siblings had a probability of surviving of 75 per cent. Dr Lummaa suggests that this is likely because elder siblings often help parents to raise theyr younger siblings and provide care.
So, if you’re a younger sibling who is still single, you can blame your elder siblings for not being married but you’ll have to thank them for your adulthood at the same time!
