ふくそうせつ
輻輳説
convergence theory (developed by William Stern):
人間の発達は生まれたときから持っている素質（能力や性質）と環境的要因の両方が作用することで現れるという考え方。シュテルンが発表した考え。
The way of thinking that human development is realized by the actions of both a person's innate qualities (abilities and nature/character) and environmental factors. This idea was presented by William Stern.