This study gives evidence that women in Norway who are already managers might be better leaders than men based off 5 criteria. Right off the bat I see two issues that give me cause for concern.
When dealing with something such as "what makes a good leader", every answer is going to be dependent upon who is being led. This study does give evidence that women in Norway might lead people in Norway better than men in Norway (the study didn't say if they used Norwegian people or just people in Norway). Obviously there are cultural differences that might change the results for other locations.
"who are already managers"
This is the big issue with this study that makes it questionable as to whether the is any evidence in this study about women in the general population or even the Norwegian population. By only looking at people who are already managers, this study is exposing itself to a large amount of survivorship bias. As a simple example imagine everyone gets a leadership "rating" between 1 and 10. 5 men have leadership rating of (8,7,5,3,2) while 5 women have leadership ratings of (10,7,3,1,1). If we only look at the top 2 for each category, we find that women are better leaders than men with an average leadership rating of 8.5 compared to the men's average of 7.5. But if we look at the entire population, the average for women is 4.4 while the average leadership rating is 5. While it's never as simple as this scenario, it's reasonable to expect the men and women in Norway who are managers were not selected randomly. Thus this survey is not an accurate representation of the population of Norway (let alone the whole world) and should not be applied as such.
All information taken from OP's source