A study from the University of California, Davis has found your parents do have a favourite, and it is probably their first born.
Research by the Family Search Group, and the University of California has found that 74 per cent of mothers, and 70 per cent of fathers admitted to having a favourite child.
The 2005 study included 384 families and was published in the Journal of Family Psychology, including interviews with siblings themselves, who were never more than four years apart in age.
It found that young siblings generally felt the eldest was the favourite.
Professor Katherine Conger who co-authored the study, admitted that she and her team had expected this to be the other way around.
I was a little surprised. Our hypothesis was that older, earlier-born children would be more affected by perceptions of differential treatment due to their status as the older child in the family.
According to the study, completing a life mile stone or task first (as an older sibling will usually do), makes the eldest more confident and assertive than their younger siblings.
First born children also felt they were receiving preferential treatment, because their 'accomplishments' meant more to their parents as significant goals, simply because they were the first time parents had experienced such parental pride.
The younger siblings felt the attention given to their parents had knocked their confidence.