New research has revealed that eldest children are usually cleverer than their younger brothers and sisters as they receive more mental stimulation in their formative years.University of Edinburgh economists found that first-born children achieved higher IQ test scores – even as young as one-year-old.
Basically, parental behaviour changes with children. First-borns are apparently given more support when young, and aided more with guidance in thinking. According to the study, which was published in the Journal of Human Resources, all this isn't to say that parents don't love their youngsters as much.
It's just that mums and dads spend less time carrying out brain-stimulating activities with younger kids. Not as much reading time, music practice, and so on – things that help development.
Also, it appears parents are more likely to take increased risks with second, third, etc. kids. They're more likely to smoke, for example.