I like to think of the characteristics of women and men as overlapping ovals (it also works with two bell curves that are slightly offset from each other). For each gender, there is a lot of variety, and the differences between people of the same gender can be huge. The ovals on this page have centres which reflect the average for each gender. As you can see, the averages of for each gender are different. That’s what’s meant by gender differences. Women and men are differently psychologically, have different talents, act and behave differently.
In this illustration, the averages for each gender are closer together, i.e. they are more similar, than the extremes for each gender. I believe that is true. Women and men are different, but not as different as individuals of the same gender can be from each other. Popular culture (such as "Men are from Mars, women are from Venus") often portrays men and women as being very different, with a lot of stereotypes attached to each gender. In reality, gender differences are about averages and say little about the behaviour of individuals. If trait X is stronger in women, it means the average woman exhibits X slightly more than the average man – in individuals, trait X follows a normal distribution or bell curve and can be strong or weak in both men and women.
The sides of this graph show extreme gender-specific behaviour — the light blue area to the left would be for men with very masculine behaviour; the light pink area would be for women with very feminine behaviour.
"Most behaviors are normally distributed for each gender with small differences between the genders emerging only for very specific abilities and contexts. The research on this says that we are not clearly and distinct dichotomized gendered forms as humans. There is clearly a lot of overlap." – Dan Karasic, Associate Clinical Professor of Psychiatry at UCSF, 2003.