Parallel Lives
by Frank J. Sulloway
教育の世界で遺伝のことを語るにはちょっとした勇気がいりますが、科学の世界では有体に次のようにも言われています。
Genetic influence is now known to account for between 80 and 90 percent of individual differences in height, which is why identical twins usually differ in stature by less than an inch. Similarly, genes are responsible for about 70 percent of individual differences in weight, about 60 percent of individual differences in general intelligence, and contribute less, but still substantial amounts of variance, to most behavioral traits. According to Segal and other twin researchers, as much as 50 percent of the variance in personality traits appears to be explained by genes, with somewhat smaller degrees of variance accounting for occupational interests (40 percent), social attitudes (30-40 percent), and job satisfaction.
NYR October 30, 2006. p. 39
そうなると古典的な”nature or nurture”はnatureに軍配が上がったのかというと、そうでもなく、現在は”nature via nurture”と考えられているそうです。人は、遺伝情報に導かれてある種の環境を好んで選び、その環境の中でその人らしさが作られてゆくといったところでしょうか。
[M]ost people, driven in part by their genetic blueprints, chart adaptive routes during their long voyages through life by creating their own environments – a phenomenon that has come to be known as “niche picking.”
In short, Galton’s old distinction between “nature and nurture” has been substantially replaced in recent years by a view of life as a continuous process of genetically influenced interactions with the environment – a process that encompasses what has been termed “nature via nurture.”
NYR October 30, 2006. p. 41
東洋的な言い方をすれば、「宿命」と「運命」。
宿された命に応じて、命を運ぶのが人生なのかもしれません。