Family birth order is crucial to the development of personality because it can dictate how we interact with others from a young age. We all develop a mantra.

For an older child it might be: “I should be the one in charge.”
For the only child it might be: “I only count in life if I get along with other people.”
For the youngest child it might be: “I may be last, but I am not going to be least.”

Having a relationship that compliments your birth order position has the best chance of long-standing happiness. Which sibling is the best match for you?

First-born & first-born:
Eldest children are used to taking charge because parents often ask them to help out with the care of younger siblings.

Celebrity Couple: Kate Middleton & Prince William

First-born & middle child:
Middle children have the best track record for staying faithful, possibly because they learn to make the best of being squeezed in the middle as children — and are willing to be accommodating.

Celebrity Couple: Michael Douglas (first-born) and Catherine Zeta-Jones (middle child)

First-born & youngest child:
The odds of a happy marriage are highest when first-born women marry a last-born son. A youngest son will have experience of understanding and learning to deal with a more dominant woman. Youngest children tend to be the funniest members of families.

Staci & Husband #1: Youngest (Staci) & Oldest (him)
Staci & Husband #2: Youngest (Staci) & Oldest (him)

Middle child & middle child:
One of the most difficult combinations to make work. (Middle children were overpowered by the first born and then undercut by the youngest.) Tend to be very cautious about telling the truth about feelings because they worry they won’t be heard. Have a date night once a week and have as many conversations as you can about everything from money and sex so your needs both get heard.

Middle child & youngest child:
Middle children do not expect to get their own way. Youngest children do. Middles are likely to indulge last-born children’s tendency towards more creative and risk-taking careers. There may be less order and not as much goal-directed behaviour in this pairing, but the relationship has more chance of being an amicable one.

Youngest children need to check they are not always trying to be the centre of attention — at the expense of their spouse. Middle-born children may also have to stand up to youngest children to bring them back down to earth and make sure they act in the interests of
the whole family, not just their own.

Celebrity Couple: Emily Blunt (middle child) and John Krasinski (youngest)

Youngest child & youngest child:
Two youngest will have always kept their position as the most indulged member of their families. This means neither will have completely grown up.

Celebrity Couple: Blake Lively and Ryan Reynolds
Hutch & Nicole: Youngest & Youngest

Only child & first-born:
Only children have never known the shattering feeling of being displaced by a new arrival. Both eldest children and only children expect to be in charge.