Affection between male adolescents and men is a very warming and refreshing facet of Greek culture, with unabashed signs of physical affection that have nothing to do with sex, but everything to do with friendship.
Girls too, can be seen walking hand in hand or arm in arm. Greek men, especially in villages, but in general even in the cities, tend to respect women and to be unaggressive towards them (and often paternal) though caution should certainly be observed by women travelling in Greece, given the reality of the famous type known as the 'kamaki' (lit. harpoon), which describes (usually youngish) men known for hunting foreign women (though these types generally hang out in tourist spots), and because there are always exceptions to the rule.
The instinct to reassure and relax others is built into the Greek character, another manifestation of the affection that is related to warm and nourishing family ties. No one is expected to be perfect, and no one is allowed to worry too much. The expression 'Den Be-razei' (which is best expressed in English by the words 'Never mind' or 'Don't worry about it') is one of the most common Greek expressions, as is 'Mi se niazei' (same thing), or 'Min anisiheis' ('Don't be uneasy', literally). One also hears the expression 'Siga siga' frequently in Greece, which means something like 'Take it easy' or 'Gently does it', or 'Give yourself time'.