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SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 146 
conditions. In later times, commerce, the interchange of ideas, the 
moving aboiit of certain craftsmen, and the close interrelations between 
groups contributed to the formation of a cultural pattern unique to 
Mesoamerica, which ceased to exist only after the arrival of the 
Spanish. 
The fact that some cultures reached a greater peak of development 
than others is not so much the result of the geographical situation in 
which they developed, but rather the conjunction of various cultural 
factors, such as technology, social organization, commerce, popula- 
tion concentration, accumulation and interchange of knowledge, 
which led to greater achievements, encouraged in turn by the economic 
stability of these societies. 
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