There are many families amongst the refugees but if you look at the population of the UK, for example, a very large proportion of young men between 16 and 30 are not in a permanent relationship, and this is a country where cohabiting out of wedlock is not frowned upon.  There are an equal number of 'unattached' women.

So if we accept that there are three basic groups, families, single men and single women in a crisis situation such as there is in Syria which of those groups are most likely to be able to undergo the rigours of long distance travel and which are likely to end up in so called safe havens such as have been set up in the Lebanon and Jordan.

Of course young single men are likely to be the most numerous amongst those reaching the shores of Europe.