The reason the youngest sibling is actually more likely to be the favourite.

If you needed a little more proof the youngest sibling in your family may well be the one enveloped in the most love and affection, look no further.

According to a new study, the youngest sibling is in fact more likely to be the parents’ favourite. However, and most confusingly, it has a lot to do with them simply assuming they’re the favourite.

Researchers from Brigham Young University’s School of Family Life studied 300 families each with two teenagers, and found perceptions of favouritism had a huge impact on which child was the favourite.

In simple terms, it works a little bit like this: If a youngest sibling assumes they are the favourite child, and the parents agree, the relationship and bond is strengthened. On the other hand, if a child has less confidence in themselves being the favourite, then the bond is weakened.

The researchers believe at the crux of their conclusion is the knowledge younger siblings will inherently compare themselves to their other siblings rather than the other way around.

Analyses revealed that siblings' perceptions of being favoured predicted less conflict with and greater warmth from both mothers and fathers, primarily for secondborn adolescents.

“It’s not that first-borns don't ever think about their siblings and themselves in reference to them,” BYU School of Family Life assistant professor Alex Jensen told The Independent. “It’s just not as active of a part of their daily life.

“My guess is it’s probably rarer that parents will say to an older sibling, ‘Why can’t you be more like your younger sibling?’ It’s more likely to happen the other way around.”