Researchers have long had evidence that first-borns tend to be more dutiful and cautious than their siblings, early in life and later, but previous studies focusing on I.Q. differences were not conclusive.
Researchers have long had evidence that first-borns tend to be more dutiful and cautious than their siblings, early in life and later, but previous studies focusing on I.Q. differences were not conclusive.
研究者很渴望一些证据，即无论早期晚期，第一个出生孩子比他们的兄弟更具有责任感以及更谨慎，但是以前的研究仅仅聚焦于智商上的区别而不是决定性的原因上。