Before getting into the discussion of whether a person's position in their family affects their personality, Claire Byrne wanted to make sure that Dr Ann-Marie Creaven from the Department of Psychology at the University of Limerick and mental health specialist Dr Harry Barry declared where they come in their respective families. Just to make sure it was out there.

So, Ann-Marie is a first-born child, Harry is a second-born and Claire herself declares her sort-of middle-child status (she's one of six children). With everything above board, the discussion proceeded.

Harry noted some similarities between his patients over the years and where they came in their families:

"There’ll always be subtle differences from family to family, but it’s amazingly consistent how the same patterns will keep turning up over and over again. And I think, you know, even with changing demographics and smaller families and all the rest of it, we’re still going to see lots of evidence of these characteristics coming up. So it’s a very important topic and it does actually, you know, jokes aside, it does actually impact on our future life and how our relationships will be and even on our mental health."

Ann-Marie highlighted the fact that the way parents tend to raise their children can vary significantly from first child to subsequent children:

"Later-born children in large families, one study found they're at greater risk for hospitalisation for avoidable injuries, probably because parental attention is that bit more stretched. And there’s other research suggesting that parents have more communication with first-borns about sex and relationships because for younger siblings, their older siblings sometimes take some of that on."

And an even more consistent parenting trend tends to emerge when eating behaviour is examined. Where you come in your family can make a big difference in the sort of foods you get exposed to from a pretty early age, as Ann-Marie explains:

"I’m sure for the first-born, many of us can identify, you know, you steam the organic broccoli, you blitz it and you freeze it and you do all these things and I’m sure Claire in your house by the time you got to number six, maybe, do you know, maybe a bowl of cereal for dinner was okay some days. So there are differences in eating patterns according to your birth order."

Of course, as a first-born child, Ann-Marie is likely to relate to what Harry has to say about the characteristics of the child that sets the precedent in a household and teaches parents how to be parents:

"They obviously get the full attention of their parents from day one. They’re very interesting because they’re actually going to be the ones who break the mold. They’re going to be more organised, they’re going to be often very responsible, they feel that they have to achieve more, their parents expect them to look after siblings coming up."

Being a first-born child can come with other expectations as well, not all of them obvious or necessarily welcome:

"As parents age, there’s this slight almost pressure on the oldest or the first-born to look after them."

First-born children usually means first-time parents, Ann-Marie points out, and that’s why the organic steamed broccoli tends not to make its way down the line when more children enter the picture.

It’s also why younger siblings often have an easier time of it than first-borns when it comes to parental discipline:

"The first child in a family is the first time parents get to be parents so it’s the only time they’ll have this concentrated focus on one particular child. So that’s really them learning how to be parents and then they tend – and studies show this – to be a little bit more relaxed with subsequent children that come along. But of course that doesn’t mean children in different birth orders have different personalities, it just means they’re reared in a slightly different way."

So your predilection for terracotta armadillos is not really down to the fact that you’re the fourth of five children, it’s just a result of the way you were reared. But at least you’re likely to be spared the caring roles that can be thrust at many first-borns. Ann-Marie:

"The first child as well can see the parents looking after the younger siblings and is more exposed, I suppose, to caring roles. So we do sometimes see expectations for caring roles for first-borns in terms of caring roles later. But I will say in defence now of the younger siblings, that, simply by virtue of age, younger siblings are less likely to have children of their own and often because of that they might be expected to fulfil caring roles that they haven’t signed up for and that aren’t necessarily part of their life plan, so it can work that way as well."

The story gets more complicated when it comes to adopted children, blended families (how does it work when you’re the eldest in your original family, but the second eldest in your new family?) and first-born twins, triplets, etc.

You can hear Harry and Ann-Marie's take on those scenarios, as well as the rest of the discussion, by listening above.