An image of two siblings playing Nintendo.

The oldest child is actually the smartest, study claims

Older siblings often like to lord over younger brothers and sisters, proclaiming themselves to be wiser, more intelligent, and more successful. There have been plenty of heated arguments about this, both over the dinner table and in the world of academia. But now, a new scientific study claims to have settled the matter for good, proving what younger siblings have always feared: the eldest really is the smartest.

Now, before some of you get totally outraged, let's look at the findings of the boffins first. The study, which was recently published in the Journal of Human Resources, and entitled 'The Early Origins of Birth Order Differences in Children’s Outcomes and Parental Behavior,' claims that parents languish more attention and care on their firstborn child, and inadvertently become more complacent with subsequent offspring.

The researchers examined statistics from the National Longitudinal Survey of the Youth, which includes information on thousands of Americans between the ages of 14-21. These minors were first interviewed in 1979, and have been regularly re-interviewed since that time, on a wealth of subjects relating to their employment, income and education.

From the data they examined, they found that parents gave the same amount of love and care to all their children. But they noted that the firstborn child tended to receive the most mental stimulation; as the number of children within the family unit increased, parents were unable to keep up that level of stimulation for subsequent children.

Speaking to TODAY magazine, the study's co-author Jee-Yeon K. Lehmann stated: "We were surprised by the finding that birth order differences in cognitive test scores and parental behaviour appeared so early. First-time parents tend to want to do everything right and generally, have a greater awareness of their interactions with and investments in the firstborn. With each subsequent child, parents tend to relax to a greater extent what they might deem as non-essential needs for their kids."

A pair of siblings playing together. Credit: Getty

She added: "The lesson here for parents is that the types of investments that you make in your kids matter a lot, especially those that you make in the children’s first few years of life. All those learning activities that you did with your first child as excited, nervous and over-zealous parents actually seem to have some positive, long-lasting impact on their development."

The study also claims that pregnant mothers are less likely to cut down their alcohol intake while gestating subsequent children, to seek prenatal care later, and to breastfeed their other children.

So there you have it: older siblings really are better off. Don't lord it over the young'uns too much though guys: it's likely to cause a lot of tension.