Proud parents make eldest children the smartest - but it's love that counts most
First-born children are smarter than their siblings and it's the parents that make them that way. By the time younger siblings come along, parents are too worn out and stretched too thin to invest as much time in them.
Researchers from the University of Edinburgh, the University of Sydney and economic consulting firm the Analysis Group analysed data for approximately 5,000 US children enrolled in the National Longitudinal Survey of Youth.
By analysing the results in relation to parental behaviour, they found first-borns were given more support with tasks that involved thinking, and subsequently scored better on the tests.
It's true, first-borns receive more mental stimulation. Think about all the new parents playing classical music to their children before they are even born. First-borns have endless books read to them, and songs sung to them.
The first-born gets the best buggy on the market, the new cot, the new clothes, the new toys. By the time the youngest comes along the parents will be happy to wheel them around in a wheelbarrow, just about throw a nappy on them and let them play with a saucepan.
The first-born gets fresh parents, the youngest gets sleep-deprived, worn out, weary, older parents.
The first-born gets a standing ovation every time they look sideways. The youngest could recite Seamus Heaney's entire collection of poetry and be told to "be quiet and eat your dinner".
The eldest child has parents who queue up at six in the morning to get the front row in the school Christmas play. They will video their child's every move and watch enraptured as their eldest child stutters through their one line.
The youngest child will get the, "of course we were there, we were just down the back", line when their parents forget the show is even on.
The first-born is stimulated with flash cards, 'educational' TV shows and walks in nature every weekend. The youngest is plonked in front of the TV, regardless of what mind-numbing rubbish is on, for hours while their sleep-deprived parents valiantly try to get through the mountain of laundry that has piled up and take sneaky naps on the couch.
The first-born gets the puréed green veg and sugar-free diet. The youngest is handed sweets stuck to the floor of the car to keep them quiet.
The study did show, however, that all children receive equal amounts of emotional support from their parents. It's just the brain-stimulating activities that fall by the wayside. This could be due to the fact that by the time the youngest comes along the parents' own brains have turned to mush from sleep deprivation.
Eldest children have also been shown to be more successful and ambitious than their siblings. They are 16pc more likely to pursue higher education than younger siblings.
But before younger siblings go to their parents and demand retribution, the eldest don't have it easy. Parents are harder on their eldest children and expect more.
Oh yes, there is payback due for those hours of finger painting and lullaby singing. All of the new parents' hopes and dreams are put into that first baby.
The first-born is also the guinea pig of the family as new parents stumble through the first years trying to do their best but undoubtedly making mistakes.
New parents have no idea how to raise a child. Each step causes the parents to venture into unknown territory.
Should they give time-outs for bad behaviour or take away internet or TV privileges for a bad report card?
How many of us have shouted "that's it, no more TV ever" to our eldest? Would you dream of saying that to your youngest? No way. Having them quietly watching TV can often be the best part of your day.
Research has shown that parents put less pressure on their later-born kids. Parents are more likely to have stricter rules for their first-born children for everything.
Also good news for the younger siblings, they tend to be healthier because they have been exposed to bugs earlier in life.
Think of the amount of time and energy new parents spend sterilising every single thing their eldest child touches, whereas the youngest can often be found drinking water from the dog's bowl.
When all is said and done, every parent just wants the best for all of their children.
While it's certainly true that more time and energy is invested in stimulating activities with the eldest child, the siblings that follow are loved every bit as much.
Parents shouldn't beat themselves up about not spending the same amount of time making clay elephants or fairy cakes with all of their children.
Just love them and hope for the best.