Professor links countries' military strength to number of 'superfluous sons'
                                
                                
                                    (Newser) -
                                    A nation’s military strength may be rooted in its average family size, says a popular German professor, putting Islamic countries in a good position, America on neutral ground, and Europe in dire straits. Bigger families mean “more superfluous sons to burn on the battlefield,” argues Gunnar Heinsohn....