She studied the phenomenon cross-linguistically.    From Wordnet, Princeton University. 

Humanness is a core part of grammar cross-linguistically.    From Wordnik.com.  [Singular “they” and the many reasons why it’s correct « Motivated Grammar] Reference

It so happens that all three of these classes of consonants often have the effect of lowering adjacent vowels cross-linguistically.    From Wordnik.com.  [Pre-IE and alternating thematic vowels] Reference

Notably, Freeman points out that one of the only is attested cross-linguistically, further destroying the notion that one of the only is somehow illogical.    From Wordnik.com.  [2009 March « Motivated Grammar] Reference

It's important to note however that the close semantic association between 'joy' and 'drunkiness' is pervasive cross-linguistically, as Sanskrit मद्- mad- 'to be glad; to be drunk' and the English phrase 'drunk with joy' show us.    From Wordnik.com.  [Drinking in more of the drunk-joy connection] Reference

Have been misunderstood as /mχadu/, been borrowed as such directly into PIE (as opposed to Pre-PIE), and then (very quickly, I imagine) the phonotactically forbidden (and cross-linguistically rare!).    From Wordnik.com.  [Enticed by a drunken thought] Reference