Liittschwager and Markman (1994) have suggested that mutual exclusivity, the phenomenon in which children tend to apply new words to novel referents for which they do not know a label, is an automatic cognitive process and can only be overcome by expending additional cognitive resources. More recent work by Piccin and Blewitt (2007) suggests a different explanation, that mutual exclusivity is instead caused by conservation of cognitive resources that can be reallocated to meet situational demands (e.g., learning words in a new language) without the use of additional resources. An experiment was conducted with 35 3- and 4-year-old children to test these two hypotheses by teaching new words to children in two different conditions; in one condition children were told the target words were foreign, and in the other, that they were English. Results showed a mutual exclusivity effect in both conditions, but did not show any effect of believing the words to be from a different language. Participants in both groups had equal difficulty learning synonyms relative to nonsynonyms, supporting Liittschwager and Markman's hypothesis.