Lead researcher David Lawson of University College London said: “Traditionally, aristocratic families tended to give the first heir more wealth. That impulse may be culturally ingrained. Richer families have more time and money to afford surplus benefits for their kids like a good diet, helping with homework and time to read to them at night. These benefits are diluted sharply as more children are born.”
In their study, involving 14,000 families in Britain, the researchers analysed the effect on offspring by the number of siblings as well as their parents’ wealth and found a clear “later-born disadvantage”, ‘The Sunday Times’ reported.
There is evidence from elsewhere to back up the idea that the extra care and attention may lead to greater success in later life for older children, according to them.
Describing the habits of richer families, they said: “Each additional sibling markedly reduces the amount of care that both mother and father give to each child. We find clear evidence of a later-born disadvantage with the presence of older siblings linked to a larger deficit in parental care. Strong birth order effects on IQ and health outcomes have also been demonstrated in modern populations consistent with a later-born disadvantage.”
But, why should similar effects be weaker in poorer families? This is because there are so few resources it is harder to give one child much more time, love or possessions than another, the researchers said.