史騰(stern)將智力發展的內在潛力比喻為橡皮筋，
因為個人受遺傳的智力發展潛能不同
而環境則是在橡皮筋上施予的拉力，
進而可能達到更高程度的智力；
像教育的功能就是在延伸橡皮筋，
使個體達到遺傳限的上限。

Stern's Rubber Band Hypothesis says that a person's ability to reach genetic potential is affected by the environmental forces that stretch to a set limit (parallel to the length of the rubber band) or don't stretch it