Characteristics of the first child predict the parents' probability of having another child

Area of Science:

• Developmental Psychology
• Family Studies
• Behavioral Genetics

Background:

• Parental decisions regarding family size are influenced by numerous factors.
• The impact of firstborn child characteristics on subsequent sibling conception remains an area of interest.

Purpose of the Study:

• To investigate if the firstborn child's traits predict parents' timing and likelihood of having a second child.
• To explore the association between infant temperament, childhood behaviors, and cognitive abilities with subsequent childbearing.

Main Methods:

• Utilized data from the British Millennium Cohort Study (N=7,695 families).
• Employed survival analysis to model the time to a second child's birth.
• Assessed child characteristics using the Carey Infant Temperament Scale, Strengths and Difficulties Questionnaire, and Bracken School Readiness Assessment.

Main Results:

• Low infant reactivity, high prosociality, low conduct problems, and high cognitive ability in the firstborn were linked to a higher probability of parents having another child.
• These associations generally strengthened over time, except for reactivity to novelty.
• High emotional symptoms in the firstborn showed a positive association, potentially due to reverse causality.

Conclusions:

• Child characteristics, particularly cognitive ability, adaptability, and prosocial behavior, appear to influence parental decisions about future childbearing.
• These findings highlight the role of 'child effects' in shaping family dynamics and reproductive timing.
• Further research should consider the bidirectional influences between child characteristics and parental decisions.