If you're the eldest in your family, chances are you've known this all along.

If you need some extra ammo for your argument however, the latest scientific study has laid it out in black and white: first-born children are more intelligent than their siblings. A team from the University of Edinburgh have determined that enjoying the full attention of both mum and dad makes for smarter kids. In fact, the results of the study, published in the Journal of Human Resources, show that eldest children demonstrate higher IQs... even at the tender age of one. Using data from the US Children of the National Longitudinal Survey of Youth collected by the US Bureau of Labour Statistics, the research involved 5,000 children who were monitored from before their birth until they were 14-years-old. The findings could go some way in explaining the so-called birth-order effect, which some believe can leave an indelible impression on an individual and the way they live their life and deal with friendship, love, and work. Commenting, Dr Ana Nuevo-Chiquero, of the University of Edinburgh's School of Economics, told The Standard: "Our results suggest that broad shifts in parental behaviour are a plausible explanation for the observed birth order differences in education and labour market outcomes." The researchers were clear on one thing: It doesn't mean that eldest children get more love than their younger brothers and sister, just more attention in their formative years. So, while you might be the eldest and possibly the smartest, there's no concrete proof you're mummy and daddy's favourite. Although you could blame your older siblings for your dodgy life decisions.