Probability is one of the many factors which influence phonetic 
variation. Contextual probability, which describes how predictable a 
linguistic unit is in some local environment, has been consistently 
shown to modulate the phonetic salience of words and other linguistic 
units in speech production (the probabilistic reduction effect). In this 
paper we ask whether the probabilistic reduction effect, as previously 
observed for majority languages like English, is also found in a 
language (Kaqchikel Mayan) which has relatively rich morphology. 
Specifically, we examine whether the contextual predictability of words 
and morphemes influences their phonetic duration in Kaqchikel. We find 
that the contextual predictability of a word has a significant effect on 
its duration. The effect is manifested differently for lexical words 
and function words. We also find that the contextual predictability of 
certain prefixes in Kaqchikel affects their duration, showing that 
contextual predictability may drive reduction effects at multiple 
levels of structure. While our findings are broadly consistent with many 
previous studies (primarily on English), some of the details of our 
results are different. These differences highlight the importance of 
examining the probabilistic reduction effect in languages beyond the 
majority, Indo-European languages most commonly investigated in 
experimental and corpus linguistics.