Gender is not defined. There is no inherent thing like girly behaviour and boyish behaviour. The whole thing is socially constructed. An individual react to different situations differently depending on his or her socio-economic cultural background. My parents kept on telling me, "girls don't cry" from my childhood. So I never learnt to cry during a crisis. My friend finds that unnatural for a girl. Well that's how I was brought up. This socially defined paradigms girl/boy behaviour is fuzzy and interchangeable.