Birth Order and Spacing

In spite of these criticisms, research into birth order and its effects on personality, behavior, achievement, and intellect continue. In fact, a comprehensive research project on birth order by Frank Sulloway, called Born to Rebel (1996), seems to refute much of what Ernst and Angst questioned in regard to the significance of birth order on personality and development. Sulloway does this through the use of a sophisticated scientific method called meta-analysis, in which pooled studies are used to increase the statistical significance. In other words, the more data that are examined, the less likely there is for error to occur. It is important to note that as Sulloway reviewed the criticism of Ernst and Angst, he was able to find 196 birth order studies that did meet the standards for what these two researchers called "properly controlled research." Sulloway subsequently examined the five main personality traits and how these relate to human development: openness to experience, conscientiousness, agreeableness, neurosis (emotional instability), and extroversion. Out of 196 studies, 72 of them substantiated the following components:

• Openness to experience: Firstborns are more conforming, traditional, and closely identified with parents.
• Conscientiousness: Firstborns are more responsible, achievement-oriented, and organized.
• Agreeableness: Latterborns are more easygoing, cooperative, and popular.
• Neurosis (emotional instability): Firstborns are more jealous, anxious, neurotic, and fearful.
• Extroversion: Firstborns are more outgoing, assertive, and likely to exhibit leadership qualities.

In addition to contradicting much of the criticism aimed at birth order research, Sulloway's research details his efforts to gather data on thousands of people who were involved in historic controversies. He wanted to know what set apart the rebels from the reactionaries throughout history. His conclusion is one that suggests family structure, not necessarily church, state, or economy, as the impetus to historical change. He makes a case that firstborns, whatever their age, sex, class, or nationality, specialize in defending the status quo while latterborns specialize in toppling it.