  Birth Order Compatibility: Your Best -- and Worst -- Matches for Love by Dr. Kevin Leman [http://www.ivillage.com/relationships/experts/experts_by_month/articles/0,9632,172420_285328,00.html] First Born Married To A Middle Child: The danger here is that the middle-born may modify his or her own behavior to please the first-born mate. While the middle makes a good general match for anyone (except, perhaps, for another middle), she may find the first born to be somewhat intimidating and thus need drawing out. If you marry a hard-driving first-born, you may be inclined to give up your own desires and dreams to please your more dominant, first-born spouse.
However, if you have last-born tendencies, this can be a very good match for you. Birth Order and Your Personality: 8 Facts That Might Surprise You [http://www.ivillage.com/relationships/experts/experts_by_month/articles/0,9632,172420_285364,00.html] First-Borns Positives: They are natural leaders. They represent United States presidents, astronauts, and CEOs by overwhelming numbers. They frequently live with a sense of entitlement and even superiority. They often come in two flavors: compliant nurturers/caregivers or aggressive movers and shakers. Both are in control; they just use different methods. As a rule, first-borns are picky, precise people -they love paying attention to details -and they tend to be punctual, organized, and competent. They want to see things done right the first time. They don't like surprises. Negatives: They are often moody and occasionally lack sensitivity. They can be intimidating, particularly by pushing people too hard or refusing to take no for an answer.
Sometimes they can be a bit of "know-it-all," and often are poor delegators, in large part because they don't trust other people as much as they trust themselves. They also tend to be bossy, flaw pickers, and conscientious to a fault. Middle-Borns Positives: The classic middle-born is very relational, tends to be a people-pleaser and usually hates confrontation. Their basic need is to keep the oceans of life smooth, and their motto might be 'Peace at any price.
' They are usually very calm, will roll with the punches, and are amiable, down-to-earth, and great listeners. They are skilled at seeing both sides of a problem and eager to make everybody happy. That makes them good mediators and negotiators. Negatives: They tend to be less driven than first-borns, but are much more desirous of having everybody like them -- or at least happy with them. They have a difficult time setting boundaries. They can drift into becoming 'codependents' as they try to please everybody. They are not good at making decisions that will offend others. They also tend to blame themselves when others fail. 
