Endearing desire to help out actually signals fairly sophisticated brain development, and is a trait of interest to anthropologists trying to tease out the evolutionary roots of altruism and cooperation.

• 蹒跚学步的幼儿想帮助他人的可爱愿望真实地反应了大脑向成熟方面的发展,对试图尽力释疑利他主义和合作精神的进化根源的人类学家来说,这种信号带有利益的特征。