And this is thoroughly discussed in the article. It's a sample of men from Harvard. However, it is a very long, in-depth study.
Just as you can argue that it can, at best, indicate correlation - and only apply to white Harvard men... it's also possible that the lessons learned are applicable to people outside that narrow scope. It's possible. But then it's also possible that the internal opinions, biases and struggles of Vaillant are bleeding into the conclusions as well.
Just as you can argue that it can, at best, indicate correlation - and only apply to white Harvard men... it's also possible that the lessons learned are applicable to people outside that narrow scope. It's possible. But then it's also possible that the internal opinions, biases and struggles of Vaillant are bleeding into the conclusions as well.