What if we could study people from the time that they were teenagers all the way into old age to see what really keeps people happy and healthy?
Хүмүүсийг юу аз жаргалтай  болгодгийг мэдэхийн тулд тэднийг өсвөр настайгаас нь эхлээд хөгшрөх хүртэл нь судалбал ямар вэ?