On the other hand, L1 attrition may also occur if the overall effort to maintain the first language is insufficient while exposed to a dominant L2 environment. Another recent investigation, focusing on the development of language in late bilinguals (i.e. adults past puberty), has claimed that maintenance of the mother tongue in an L1 environment requires little to no maintenance for individuals, whereas those in the L2 environment have an additive requirement for the maintenance of the L1 and the development of the L2 (Optiz, 2013).