Bryan Caplan recently discussed an article published in the Journal of Marriage and Family about how kids aged 0-12 spend their time and how the activities in which they engage affect their academic achievement.
The authors of the article controlled for a whole host of individual factors such as income, family characteristics, race, sex, and investigate many factors thought to drive academic achievement such as leisure, housework, being in school, studying, doing sports, going to church, watching TV, etc.
Bryan focuses on the somewhat surprising results that TV doesn't do much harm and studying or being in school don't (at the margin) have much of a positive impact. He also discusses one of the two consistently statistically significant factors: reading. I found the other significant effect more interesting.
That other big driver of academic achievement is called by the authors of the article "visiting." This term is just weird and seems pretty unclear until you pull up the article and execute a ctrl-f search for the word. Visiting, according to the authors, is a catchall term that means organized activity that is not church-sponsored and does not involve sports. My first thought when reading this was 4-H!
Children involved in 4-H can expect to learn a wide array of life skills and interact with a wide range of people from different walks of life and age groups. Whether you live in a rural area or dwell in the city, 4-H has something for your children. Kids learn about biology, citizenship, art, nutrition and fitness, leadership, public speaking, and more. This is all done in an atmosphere that is supportive of the child and his/her development.
So there you have it. Although the article doesn't specifically mention 4-H, this seems to me to be scientific evidence that 4-H is awesome!