Types of travel

I've been seeing many more women traveling in Central America than in other places. Especially the last few days there have been more women than men in the area. 

Looking at the type of travel, in these areas there are more projects, volunteer opportunities, mission groups etc.

I wonder if the difference is based on an idea of security or purpose, or a mix?

If men felt less secure, would they choose to travel through volunteer opportunities more often? Would it be less selfishly oriented? (Not tha volunteer trips aren't sometimes selfish). 

Just a thought