> * males are more likely (~51% of births naturally, higher thanks to sex-selective terminations in China and India.) In China, there may be more sons, but the

> * males are more likely (~51% of births naturally, higher thanks to sex-selective terminations in China and India.) In China, there may be more sons, but they're not likely to have brothers. > * males die more frequently at younger ages, so older people will have fewer brothers than younger people. Most people still consider dead siblings to be siblings.