Given that exposure to an L2 at a younger age typically leads to stronger attrition of the L1 than L2 exposure at later ages, there may be a relationship between language attrition and the critical period hypothesis. The critical period for language claims that there is an optimal time period for humans to acquire language, and after this time language acquisition is more difficult (though not impossible). Language attrition also seems to have a time period; before around age 12, a first language is most susceptible to attrition if there is reduced exposure to that language. Research shows that the complete attrition of a language would occur before the critical period ends.