The term "sibling rivalry" was coined by David Levy in 1937 in relation to the common aggressive response of an older sibling to a new baby in the family. It is also used to describe competition or antagonism between children of the same parents.
It has various causes. Freud thought it was connected to the Oedipus complex whereby sibling brothers would compete for their mother's love, or between sisters for their father's attention.
Kyla Boyse from the University of Michigan suggests it stems from a child's need to define himself or herself as an individual and to separate from a sibling.
Alfred Adler proposes that sibling rivalry is based on siblings "striving for significance" within their family.
Most psychologists believe that it stems from an innate desire to attain parental attention achieved through competing with the sibling.
Whatever the cause, the manifestation can be ugly.
Many siblings like to joke at each other's expense, which is natural - as long as they have a sense of humor - and funny. But this rivalry can be hurtful and result in siblings being unable to support each other, or have a relationship. It can result in siblings not speaking, not being there for each other and - ultimately - can negatively impact the siblings' relationship and bond.
This article from the New York Times gives various suggestions for stopping sibling rivalry and removing the tension it creates within the relationship.
- Think about your sibling as an ordinary friend, not as a relative. What do you like about him or her? What fun experiences have you shared? Why do you think the relationship should be improved?
- Do something. Think about the situation from your siblings' perspective. What can you do to support them?
- Is there something you might stop doing that would make the situation better? Discuss it openly - how can we improve things together?
- Don't be scared to apologize.
At yesterday's Olympics, brothers Alistair and Jonny Brownlee competed against each other in the Triathlon. You might have thought that this would be the ultimate sibling rivalry. However, after the brothers crossed the line - with Alistair winning gold and Jonny bronze - they threw their arms around each other in celebration.
While you can't choose your family, you can choose to make the effort to have a great relationship.
Do you, or did you, experience adult sibling rivalry? How did it manifest itself? How did you overcome it? Share your experiences in the comments below.