The Wall Street Journal examines why Finland's laid-back education system leads the world. Long story short, nobody knows. Students in Finland have smaller classes, don't do a lot of homework, don't start school until age seven, and don't move on to new academic material until everyone in their class has mastered the current lesson (therefore, the country has a tiny gap between its highest- and lowest-performing youngsters). The Finns are also a rather racially and economically homogeneous group and Finnish teaching positions are incredibly competitive--two facts that contrast sharply with the United States.
Funny thing is, a lot of what occurs in Finnish schools seems to undermine the prevailing educational wisdom. The country has self-guided student learning, starts students at a relatively late age, doesn't focus energy on high-performing kids, has little standardized testing, and separates high-schoolers into different tracks (vocational and academic). Kids can even walk around in their socks during class. Perplexing.