What makes men, men?

Over the last 50 years, our notion of masculinity has been steadily changing. Feminism and the shift in gender roles has seen increasing parity between the sexes and culturally we’re embracing a diverse array of sexual identities. So how are these changes impacting our perceptions of what it means to be a man and can men unlearn the old models of sexism, patriarchy and aggression? And are men today actually much happier in more egalitarian relationships at work and more emotionally connected with family?